"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.