If you're running macOS 10.12 or later you can gather logs for support or to see yourself what is happening with Dapper.

On versions prior to 10.12 we turn off logging in order to improve speed.

 

To enable:

Open a terminal (Applications->Utilities->Terminal)

Type in:

sudo su

[[Enter your password]]

log config --mode "level:debug" --subsystem com.map-pin.dapper.general

log config --mode "level:debug" --subsystem com.map-pin.dapper.sync

log config --mode "level:debug" --subsystem com.map-pin.dapper.mtp

log stream --predicate 'subsystem contains "com.map-pin.dapper"'

 

Now run Dapper and watch the output. Sending is a copy of the last few dozen lines helps us troubleshoot immensely.