We still haven't found the best approach for fixing this issue, but we can tell for sure that it is not connected with the sf_CmsPagePops
table. We have already scheduled this bug fix for the next release so that the solution should become part of it.
As for the restriction error message you are getting - it is not relevant in this situation as it is related to violating the Global project permissions which are set in the projects administration.
All the best,
the Telerik team