I've asked someone to reopen the issue with the steps to reproduce, because it does not have any sense to reopen it by myself, since I can't see the error. So, I don't know what to fix there.
The problem located and fixed. Reposting task status comment here.
So, there are two issues fixed:
- compatibility options for the M2Eclipse integration feature
- update site references in the both: M2Eclipse and ProjectSet integrations