Build failed to start. The following error occurred: Cannot have more than 0 builds in queue for the account

This error message indicates you're hitting a CodeBuild service quota limitation. The error "Cannot have more than 0 builds in queue for the account" suggests that your account currently has a quota of 0 concurrent builds, despite what you're seeing in the Service Quotas console.

This appears to be an account-specific issue rather than a problem with your pipeline configuration. Based on similar cases, this type of issue typically requires AWS Support intervention to resolve.

Since you mentioned checking service quotas and seeing a limit of 10 concurrent builds, there might be a discrepancy between what's displayed in the console and what's actually applied to your account.

To resolve this issue:

1. Open a case with AWS Support under "Account and billing" - this type of inquiry can be made free of charge even without a premium support plan
2. Provide details about the error message and the discrepancy between your observed quota (0) and what's shown in the Service Quotas console (10)

The issue is likely related to internal metrics that determine the default quotas for concurrent running builds in CodeBuild, and only AWS Support can properly investigate and fix this account-level restriction.
Sources
Cannot have more than 0 builds in queue for the account (codebuild) | AWS re:Post

Even if your service quotas say "10 concurrent builds," AWS CodeBuild also enforces separate concurrency limits per compute type and some accounts (especially new or sandbox accounts) have queued concurrency set to 0 by default.

This means no builds are allowed to be queued, so if one build is running, any other build attempt is instantly rejected.

Try the below ones Step 1: Check Queued Builds Quota in Service Quotas Console Go to: https://console.aws.amazon.com/servicequotas/home/services/codebuild/quotas Look for: Concurrent builds per account Queued builds per account ← likely shows 0

Step 2: Request a Quota Increase Click “Request quota increase” next to Queued builds per account (or "Concurrent builds per region" if it's 0).

Suggested request: New value: 5 (or higher, depending on your need) Region: match your pipeline region Reason: "Pipeline fails due to 0 queued builds limit. Need to enable queuing to avoid intermittent build failures.

Turnaround time is usually a few hours (faster with Enterprise or Business support plan).

Step 3: Temporary Workaround (Optional) Until AWS approves the increase: Avoid running multiple builds at once. Ensure all builds complete before triggering a new one. Use CodeBuild Batch builds if your workflow allows it runs multiple jobs in one batch).

Thanks for sharing the screenshot. Now, at least it confirms that your account already has the default 10 concurrent build limit for commonly used instance types like Linux/Small, Linux/Medium, and Linux/Large.

However, the error: "Cannot have more than 0 builds in queue for the account"

typically points to a region-specific CodeBuild queue concurrency issue that isn't explicitly listed in the Service Quotas console.

Please try the below

1. Check for VPC or Build Resource Limits If your CodeBuild project is configured inside a VPC, and there's only one NAT Gateway or limited IP availability, builds can get "stuck" and rejected if they can’t route out.

Make sure there are enough ENIs, NAT Gateway bandwidth, and CIDR IPs available.

2. Open AWS Support Case Since your quotas look good, this issue could be related to an internal backend configuration bug or region-specific throttling.

When opening a case, mention: Error Message: “Cannot have more than 0 builds in queue for the account” Region: (e.g., us-east-1) Build project name It was working before and suddenly started failing Your quota page confirms 10 concurrent builds are allowed.

Is it ok to try the below as optional? Try creating a new CodeBuild project in the same region. Or test by triggering the same pipeline in a different AWS region (e.g., us-west-2) to see if the issue is localized.

Zeros are only for xl sizes Build uses Image aws/codebuild/amazonlinux-x86_64-standard:5.0 Environment type Linux Container Compute 2 vCPUs, 4 GiB memory