CostlyOstrich36 SuccessfulKoala55 FYI
issue was in
task.set_parameters() https://clear.ml/docs/latest/docs/references/sdk/task/#set_parameters
When trying to reproduce our users issue we have set argument( dictionary ) with one of key s to be empty string and got the above error.

It would be great ClearML will output appropriate warning - something like " parameters issue" and not server error(500, Fetch experiment failed )