How I can check system defined detele button validation code
Moved from D365 general forum to the Finance forum, because it seems to be about F&O and not about D365 in general. Please let me know if you disagree.
You can't see code of F&O kernel, because it's distributed as compiled binaries. But note that that kernel often calls methods that can be overridden in the application. For example, a table may override validateDelete() method and the kernel will call this method to determine whether the record can be deleted. Plus there is other kernel logic, such as to check delete actions.