The AccdbMerge application includes several executable files. These files are available as shortcuts in the Windows menu, and at first glance, this variety may cause confusion.
AccdbMerge (32-bit) shorcuts are supposed to be used with 32-bit version of Microsoft Access, and AccdbMerge (64-bit) needs to be used with 64-bit Microsoft Access. Otherwise you will get corresponding error message in the database open progress. If none of 32-bit or 64-bit version works and progress displays errors comminicating with Access, then most likely Access component registration is broken and you need to do a full (not quick!) repair of Microsoft Office application.
Compatibility mode shortcuts are useful if any debugger/profiler software is installed on your computer that includes the COR_ENABLE_PROFILING system environment variable. The AccdbMerge application's protection mechanism will prevent it from running in such an environment. Compatibility mode shortcuts disable the COR_ENABLE_PROFILING variable for the AccdbMerge application.
Script Editor is the addional application designed to simplify creation and troubleshooting KS DB Merge scripts for the command line utility. See Scripting help for more details.