AWS Amplify build process stops with IAM role assumption error in backend deployment

Backend
1

I’ve been working with AWS Amplify Generation 2 for several months without problems. Everything was running smoothly until recently when my deployments started failing. When I push my latest changes, the build process crashes with this error message:

2025-07-24T00:22:12.992Z [ERROR]: !!! Unable to assume specified IAM Role. Please ensure the selected IAM Role has sufficient permissions and the Trust Relationship is configured correctly.
2025-07-24T00:22:13.079Z [INFO]: # Starting environment caching...
2025-07-24T00:22:13.079Z [INFO]: # Environment caching completed

I’ve already tried several troubleshooting steps. I removed the existing IAM roles and created fresh ones. I granted full administrator access to test if permissions were the issue. I double checked the trust relationship configuration multiple times. The weird part is that I didn’t modify any AWS Amplify settings recently. To confirm this wasn’t related to my recent code changes, I attempted to redeploy a different project that hasn’t been touched in weeks. That deployment also failed with the same error.

Here’s my current trust relationship policy:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Service": [
                    "amplify.us-east-1.amazonaws.com",
                    "amplify.amazonaws.com"
                ]
            },
            "Action": [
                "sts:AssumeRole"
            ]
        }
    ]
}

I also tested with this simpler version:

{
    "Version": "2012-10-17", 
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Service": "amplify.amazonaws.com"
            },
            "Action": "sts:AssumeRole"
        }
    ]
}

Neither configuration resolves the issue. Has anyone encountered this problem before? What else should I check?

2

This looks like a regional service config issue, not permissions. Since the error hit multiple projects at once, AWS probably updated their backend requirements. Make sure your Amplify app’s region matches what’s in your IAM role’s trust policy - they need to be the same region. Also check if you’ve hit any service limits on IAM role assumptions. I’ve seen this exact thing when AWS throttled certain API calls at the account level. Try deploying from a different region or reach out to AWS support to see if they’ve applied any new restrictions to your account recently.

3

that’s super annoying! have you double-checked if your IAM policies are really attached to the right role? sometimes things get tangled up, and it may help to create a new role just for testing. good luck!

4

weird timing for this to break across multiple projects… sounds like aws might have changed something on their end. try checking the amplify console settings - sometimes the service role gets disconnected randomly. also worth verifying if your aws cli credentials are still valid, mine expired once and caused similar headaches