"The breakpoint will not currently be hit. No symbols have been loaded for this document."
If you encounter this and are not able to debug X++ code in Dynamics 365 for Finance and Operations, then you need check these two options:
1. In visual studio go to Dynamics 365 > Options menu
Uncheck this option
Load symbols only for items in the solution
1. In visual studio go to Debug > Options menu
Check this option
Automatically load symbols for - All modules
Now you should be able to debug D365 code in Visual studio.