Tried renaming and deleting the ESRI folder in C:\Users\Mus\AppData\Roaming, no luck... Using Windows 7 SP1 32 bit system. When I start ArcMap 10.3 it shows the the program is initializing and loading document... but nothing opens. But ArcCatalog is working fine. Any suggestion?
We just had a similar issue with 10.4, where it wouldn't load ArcMap and then crash and give no error or indication of what happened. Event viewer and checking logs didn't show anything suspicious. It had to do with python libraries being updated back in December. You can fix this by editing your registry.
Try some of the solutions listed in Problem: ArcMap crashes during Loading Document launch stage:
ArcMap unexpectedly exits during the "Loading Document..." stage on startup. No error code is displayed.
Just go to C:\Users*%%%*\AppData\Roaming\ESRI\Desktop10.2\ArcMap\Templates => Delete "Normal" file (Or rename it). And Open ArcMap. I Did and succeeded. ^_^ Hope it is useful for you!