Invalid character in entity name when deploying

This is a Bug Report

Description

• What went wrong? After I've redeployed a certain service a few times, I receive this:

Serverless: Removing old service artifacts from S3...
Serverless: Recoverable error occurred (Invalid character in entity name
Line: 25
Column: 28
Char: =), sleeping for 5 seconds. Try 1 of 4

• What did you expect should have happened?
  I would not expect an error and I would expect it to remove any necessary artifacts from the S3 bucket.
• What was the config you used?
  Not sure how to answer this, but I'm using the AWS provider with Lambda functions. I'm also using the serverless-aws-alias plugin and deploying to a set alias.
• What stacktrace or error message from your provider did you see?
  The provider didn't have an issue - it seems strictly on the Serverless side trying to clean itself up.

Similar or dependent issues:

• Couldn't find any

Additional Data

• Serverless Framework Version you're using: 1.38.0
• Operating System: Windows 10
• Stack Trace:

Serverless Error ---------------------------------------

 Invalid character in entity name
Line: 25
Column: 28
Char: =

• Provider Error messages:

The report identifies the S3 artifact cleanup during deployment as the failing entry point, using Serverless Framework 1.38.0 with AWS Lambda on Windows 10. No source files or tests are named; start by reproducing the cleanup path, and consider the issue done when old service artifacts are removed without the entity-name error.