When creating Workflows, the following error comes up referring to the yml file:

There are OS limitations on how long an argument can be when passed to a command. In our case we use the Bitrise CLI’s validate command and pass a base64 encoded version of the bitrise.yml as an argument before saving it. The character limit is hard-coded into an OS as 131.072 and your YML might exceed this, which causes the above error.

As a quick workaround, you can either try to optimize your YML by removing some parts to make it shorter, or move some Workflows to a local bitrise.yml repository and then call bitrise run … from the original Workflow.