Reference
14 min read

Error List

You may encounter a variety of errors when you interact with the Vercel platform. This section focuses on errors that can happen when you interact with the Vercel Dashboard.
Table of Contents

The build step will result in an error if the output directory is missing, empty, or invalid (for example, it is not a directory). To resolve this error, you can try the following steps:

  • Make sure the output directory is specified correctly in project settings
  • If the output directory is correct, check the build command (documentation) or the root directory)
  • Try running the build command locally and make sure that the files are correctly generated in the specified output directory
This is only relevant if you’re using Vercel CLI 16.7.3 or older.

Suppose your project contains a package.json file, no api directory, and no vercel.json configuration. In that case, it is expected to provide a build script that performs a static build of your frontend and outputs it to a public directory at the root of your project.

When properly configured, your package.json file would look similar to this:

package.json
{
  "scripts": {
    "build": "[my-framework] build --output public"
  }
}

An example build script in a package.json file that specifies the output directory.

Once you have defined the build script, this error will disappear. Furthermore, it will not be displayed if you are using package.json purely to provide dependencies for your Serverless Functions located inside the api directory.

The maximum amount of open requests to join a team is 10. In order to allow for more requests, the existing requests need to be approved or declined by a Team Owner.

This ensures the list always remains manageable and protected against spam.

If a user has already requested access to a team, it's impossible to invite them. Instead, their request must be approved by a Team Owner for the user to gain access.

This ensures no team invites are accidentally accepted.

When the deployment for a commit fails with the message "Team access required to deploy.", the Git account of the commit author is not connected to a Hobby account that is a member of the team.

The link attached to the error allows someone to connect their Hobby account to the Git account of the commit author. If the Hobby account is connected to a different Git account, it will fail stating that a different Git account must be used to request access to the team.

Once the Git account is connected to the Hobby account on Vercel, it is possible to request access to the team. A Team Owner can then approve or decline this access request. If the request was approved, the failed commit would be retried, and the following commits would not fail due to missing team access.

A Hobby or team on Vercel can be blocked if it violates our fair use guidelines or Terms of Service.

Blocked Hobby accounts or teams cannot create new deployments, or be invited to new teams. Please contact Vercel Support if you need help.

A Project has several settings that can be found in the dashboard. One of those sections, Build & Development Settings, is used to change the way a Project is built.

However, the Build & Development Settings are only applied to zero-configuration deployments.

If a deployment defines the builds configuration property, the Build & Development Settings are ignored.

A Project has several settings that can be found in the dashboard. One of those settings, Serverless Function Region, is used to select the region where your Serverless Functions execute.

If a deployment defines the regions configuration property in vercel.json, the Serverless Function Region setting is ignored.

If a CLI Deployment defines the --regions option, the Serverless Function Region setting is ignored.

The source property follows the syntax from path-to-regexp, not the RegExp syntax.

For example, negative lookaheads must be wrapped in a group.

Before

vercel.json
{
  "source": "/feedback/(?!general)",
  "destination": "/api/feedback/general"
}

After

vercel.json
{
  "source": "/feedback/((?!general).*)",
  "destination": "/api/feedback/general"
}

The source property follows the syntax from path-to-regexp.

A colon (:) defines the start of a named segment parameter.

A named segment parameter defined in the destination property must also be defined in the source property.

Before

vercel.json
{
  "source": "/feedback/:type",
  "destination": "/api/feedback/:id"
}

After

vercel.json
{
  "source": "/feedback/:id",
  "destination": "/api/feedback/:id"
}

When running the vercel build or vercel dev commands, npm install errors can be encountered if npm was invoked to install Builders that are defined in your vercel.json file.

npm install may fail if:

  • npm is not installed
  • Your internet connection is unavailable
  • The Builder that is defined in your configuration is not published to the npm registry

Double-check that the name and version of the Builder you are requesting is correct.

If you have rewrites, redirects, headers, cleanUrls or trailingSlash defined in your configuration file, then routes cannot be defined.

This is a necessary limitation because routes is a lower-level primitive that contains all of the other types. Therefore, it cannot be merged safely with the new properties.

See the Upgrading Routes section for examples of routes compared to the new properties.

For backward compatibility purposes, there are two naming conventions for configuration files used by Vercel CLI (for example vercel.json and now.json). Both naming conventions are supported, however only one may be defined at a time. Vercel CLI will output an error message if both naming conventions are used at the same time.

These conflicting configuration errors occur if:

  • Both vercel.json and now.json exist in your project.
    Solution: Delete the now.json file
  • Both .vercel and .now directories exist in your project.
    Solution: Delete the .now directory
  • Both .vercelignore and .nowignore files exist in your project.
    Solution: Delete the .nowignore file
  • Environment Variables that begin with VERCEL_ have a conflicting Environment Variable that begins with NOW_.
    Solution: Only define the VERCEL_ prefixed Environment Variable

There are two ways to configure Serverless Functions in your project: functions or builds. However, only one of them may be used at a time - they cannot be used in conjunction.

For most cases, it is recommended to use the functions property because it supports more features, such as:

  • Allows configuration of the amount of memory that the Serverless Function is provided with
  • More reliable because it requires a specific npm package version for the runtime property
  • Supports "clean URLs" by default, which means that the Serverless Functions are automatically accessible without their file extension in the URL

However, the builds property will remain supported for backward compatibility purposes.

When using Next.js, only memory and maxDuration can be configured within the functions property. Next.js automatically handles the other configuration values for you.

It's possible to deploy Serverless Functions to multiple regions. This functionality is only available to Enterprise teams.

On the Pro plan, the limitation has existed since the launch of the current pricing model but was applied on July 10, 2020. For Projects created on or after the date, it's no longer possible to deploy to multiple regions.

To select the region closest to you, read our guide on choosing deployment regions for Serverless Functions.

The functions property uses a glob pattern for each key. This pattern must match Serverless Function source files within the api directory.

If you are using Next.js, Serverless Functions source files can be created in the following:

Additionally, if you'd like to use a Serverless Function that isn't written with Node.js, and in combination with Next.js, you can place it in the api directory (provided by the platform), since pages/api (provided by Next.js) only supports JavaScript.

Not Allowed

vercel.json
{
  "functions": {
    "users/**/*.js": {
      "maxDuration": 30
    }
  }
}

Allowed

vercel.json
{
  "functions": {
    "api/users/**/*.js": {
      "maxDuration": 30
    }
  }
}

Allowed (Next.js)

vercel.json
{
  "functions": {
    "pages/api/users/**/*.js": {
      "maxDuration": 30
    }
  }
}

If the Project configuration in .vercel belongs to a team you are not a member of, attempting to deploy the project will result in an error.

This can occur if you clone a Git repository that includes the .vercel directory, or you are logged in to the wrong Vercel account.

To fix, remove the .vercel directory and redeploy to link the project again by running these commands.

On macOS and Linux:

rm -rf .vercel
vercel

On Windows:

rmdir /s /q .vercel
vercel

Project names can only consist of up to one hundred alphanumeric lowercase characters. Hyphens can be used in between words in the name, but never at the start or end.

The amount of Vercel Projects that can be connected with the same Git repository is limited depending on your plan.

If you have reached the limitation and would like to connect a new project to the repository, you will need to disconnect an existing project from the same Git repository.

To increase this limit, please contact our Sales Team.

To verify your domain, point the domain to Vercel by configuring our nameservers or a DNS Record. You can learn more about what to do for your Domain by running vercel domains inspect <domain>, where <domain> is the domain you're interested in.

Alternatively, if you already added the domain to a project, read the configuring a domain section of the custom domain documentation.

You cannot leave a team if you are the last remaining Owner or the last confirmed Member. In order to leave the Team, first designate a different confirmed Member to be an Team Owner.

If you are the only remaining Member, you should instead delete the Team.

Deployments created using Vercel CLI will automatically ignore several files for security and performance reasons.

However, these files are not ignored for deployments created using Git and a warning is printed instead. This is because .gitignore determines which files should be ignored.

If the file was intentionally committed to Git, you can ignore the warning.

If the file was accidentally committed to Git, you can remove it using the following commands:

terminal
git rm file.txt                   # remove the file
echo 'file.txt' >> .gitignore     # append file to .gitignore
git add .gitignore                # stage the change
git commit -m "Removed file.txt"  # commit the change
git push                          # deploy the change

In some cases, signing up with GitHub fails due to GitHub's database inconsistencies.

When you connected your Hobby account with your GitHub account, the Vercel GitHub App was installed on your GitHub account and then GitHub notified Vercel that the app was successfully installed.

However, Vercel was unable to retrieve the app installation from GitHub, which made it appear as if the Vercel GitHub App was never installed.

In order to solve this issue, wait a couple of minutes and try connecting to GitHub again. If you are still unable to connect, please contact GitHub Support to determine why the Vercel GitHub App was not able to be installed.

If you have configured a custom Git branch for a domain or an environment variable, it is considered a preview domain and a preview environment variable. Because of this, the Git branch configured for it is considered a preview branch.

When configuring the production branch in the project settings, it is not possible to use a preview branch.

If you still want to use this particular Git branch as a production branch, please follow these steps:

  1. Assign your affected domains to the production environment (clear out the Git branch you've defined for them)
  2. Assign your affected environment variables to the production environment (clear out the Git branch you've defined for them)

Afterwards, you can use the Git branch you originally wanted to use as a production branch.

In order for Vercel to be able to deploy commits to your Git repository, a Project on Vercel has to be connected to it.

This connection is interrupted if the Git repository is deleted, archived, or if the Vercel App was uninstalled from the corresponding Git account or Git organization. Make sure none of these things apply.

Additionally, when using GitHub, the connection is also interrupted if you or a Team Member modifies the access permissions of the Vercel GitHub App installed on the respective personal GitHub account or GitHub organization.

To verify the access permissions of the Vercel GitHub App installed on your personal GitHub account, navigate to the Applications page and select Vercel under Installed GitHub Apps. You will see a list of Git repositories that the GitHub App has access to. Make sure that the Git repository you're looking to connect to a Vercel Project is listed there.

To verify the access permissions of the Vercel GitHub App installed on your GitHub organization, select Vercel under Installed GitHub Apps in the organization settings. You will see a list of Git repositories that the GitHub App has access to. Make sure that the Git repository you're looking to connect to a Vercel Project is listed there.

You cannot redeploy a production deployment if a more recent one exists.

The reason is that redeploying an old production deployment would result in overwriting the most recent source code you have deployed to production.

To force an explicit overwrite of the current production deployment, select Promote instead.

Certain SSL Certificates associated with your Hobby account or team (i.e. Wildcard SSL Certificates for your Vercel Project's staging domains) are automatically generated by the Vercel platform.

Because these SSL Certificates are managed by the Vercel platform, they cannot be manually deleted on the Vercel Dashboard – nor through Vercel CLI.

Custom SSL Certificates may be uploaded to teams on the Enteprise plan, which are allowed to be manually deleted.

The Git branch that is configured using the production branch field in the project settings, is considered the branch that contains the code served to your visitors.

If you'd like to assign a domain or environment variable to that particular Git branch, there's no need to manually fill it in.

By default, if no custom Git branch is defined for them, domains are already assigned to the production branch. The same is true for environment variables: If no custom Git branch is defined for them and Production is selected as an environment, they're already assigned to the production branch.

If you still want to enter a specific Git branch for a domain or an environment variable, it has to be a preview branch.

The "Command not found" error message happens when a sub-process that vercel dev is attempting to create is not installed on your local machine. You need to install the particular program onto your operating system before vercel dev will work correctly.

For example, you may see the error "Command not found: go" if you are writing a Serverless Function in Go, but do not have the go binary installed. In this case you need to install go first, and then try invoking your Serverless Function again.

You have configured one of the following for your Project:

Because the Build Command is invoked by vercel build when deploying, it cannot invoke vercel build itself, as that would cause an infinite recursion.

The same applies to the Development Command: When developing locally, vercel dev invokes the Development Command, so it cannot invoke vercel dev itself.

Adjust the Build and Development Commands defined for your Project to not invoke vercel build or vercel dev.

Instead, they should invoke the Build Command provided by your framework.

If you are unsure about which value to provide, disable the Override option in order to default to the preferred settings for the Framework Preset you have selected.

ERR_PNPM_UNSUPPORTED_ENGINE occurs when package.json#engines.pnpm does not match the currently running version of pnpm.

To fix, do one of the following:

package.json
{
  "engines": {
    "pnpm": "^7.5.1"
  },
  "packageManager": "pnpm@7.5.1"
}

You cannot use engine-strict to solve this error. engine-strict only handles dependencies.

This error occurs when attempting to create a deployment where at least one of its environment variables contains an outdated Edge Config connection string. A connection string can be outdated if either the Edge Config itself was deleted or if the token used in the connection string is invalid or has been deleted.

To resolve this error, delete or update the environment variable that contains the connection string. In most cases, the environment variable is named EDGE_CONFIG.

You must reference @vercel/speed-insights or @vercel/analytics packages in your application's package.json file. This error occurs when you deploy your application with these packages globally available, but not referenced in your package.json file, like in a monorepo.

To fix this error, add the packages to your package.json file as a dependency.

Incremental Static Regeneration (ISR) responses that are greater than 20 MB result in pages not rendering in production with a FALLBACK_BODY_TOO_LARGE error. This affects all Next.js build time pre-rendering, and other frameworks that use Prerender Functions.

These oversized pages are detected at build time and fail the build. As a temporary workaround, an environment variable can be set to ignore this build error: VERCEL_BYPASS_FALLBACK_OVERSIZED_ERROR=1.

Last updated on July 25, 2024