flashing led red apm

I had an accident with my drone where the ESC was damaged and after that my apm does not want to connect to the pc.
turns on a fixed green LED and the red LED starts to flash, manages to connect a mp but gets stuck in getting parameters

Sorry for your “little” loss
Shows that opto isolated ESC are superior. (High voltage from lipo can’t travel to the command side of the esc)

Now this is a good opportunity to replace your obsolete APM hardware with a modern Pixhawk or clone such as
Pixhawk for $84

And replace your ESC with opto isolated one such as Opto isolated ESC up to 30A per motor