I'm getting this when attempting to modify attributes defined in the general section of a workflow. This appears to be memory related, as when I restart the service the issue clears temporarily.
After reviewing the configuration elements used by the workflows, one in particular had a very large (2000+) number of items. After deleting these, the problem seems to be solved.
Is there some recommended memory setting for the wrapper.conf other than the 2048 for initial/max? I didn't see any doc values for size on this.
I would recommend to open a support request, if the issue is reproducable.
So you might get some tuning tips for the memory settings, AFAIK we don't have any public information about it.