I had this exact same record number problem when importing a GEDCOM from Family Historian. There is a workaround - it is necessary to make RM believe that the source of the GEDCOM is RootsMagic by manually editing the HEAD part and importing to a new empty database.
I have experienced this problem with various programs and a temporary solution seems to be to run software 'as administrator' until microsoft sort out a proper solution.
To be honest in the end I got fed up with it, backed up all my data and settings to an external drive, downloaded a copy of Windows 10 onto a USB flash, using the Microsoft utility. https://www.microsof...nload/windows10, and did a clean install of windows 10. This seems to have completely solved the problem - of course the downside is that re-installation of software is required.