When trying to Synchronize APM Remote with APM Foundation users need to generate a download package on the Remote Server. This may be either a differential download package or a full download package. These packages may fail to generate when the user does not have Read, Write and Modify permissions to this folder
On the Server designated to synchronize APM Remote find the following folder:
C:\ProgramData\Bentley\IvaraEXP\
Highlight the XML_DLPackages folder and select "Properties". In the Window's dialogue that opens, go to the Security tab and find the "Users" group. Update the Users group permissions to allow Read, Write and Modify.
Once this change has been made retry synchronizing the Remote.