Bug with init argument, json file and num_chains>1, cmdstan 2.28.1

No, thank YOU for the report!! I was shocked we don’t have a test for this case.

Made an issue: Unable to set init files with num_chains > 1 · Issue #1058 · stan-dev/cmdstan · GitHub

This is a pretty big one and because we also found another one for the 2.28.1 release there will be another patch release this week or the next.