non-specific exception message?

I try to edit a method config and I see this box (see attached PNG) with a blank exception message.

I think the issue is that I am "READER" on the workspace and so am unable to edit the config.

{
  "statusCode": 403,
  "source": "rawls",
  "timestamp": 1490893016756,
  "causes": [],
  "stackTrace": [],
  "message": "insufficient permissions to perform operation on cancerexomeqc/cancer_exome_qc_alchemist"
}

I found the above by looking in the network tab of the google developer tools of chrome browser