I am having the same issue – way too much z-index!
Similar issue here as well – loads of form fills in spam folder of Flamingo even though they are just regular form fills. Waiting for a solution for this.
I have the current version (1.3.83) and I am also getting this very same error. This needs to be solved ASAP, can you offer any help? It was working well and I managed to import 9 new members, but then suddenly it stopped working and trying to change from Pending membership to Approved I get HTTP ERROR 500.
Please help!