awssdk_config_override.json file not found - Exception AWSSDK

I have a very simple call to just create a new AmazonS3Client (using Java AWSSDK 1.10.12) like this:

AmazonS3 s3Client = new AmazonS3Client();

And during this call I'm getting the exception message from the AWSDK: Internalconfig.java - "awssdk_config_override.json file not found"

Actual message: 6656 [http-bio-8080-exec-8] DEBUG com.amazonaws.internal.config.InternalConfig -Configuration override awssdk_config_override.json not found.

Totally baffled what's going on here. I can currently only reproduce this on one project, but can't reproduce it when creating new projects from scratch.

Any idea what this json file is even used for? Or why it can't find it or feels the need to find it?