Magenta Geometric Shapes prohibiting entrance to the SWTOR game.

I'm getting the same thing this morning. Was working fine yesterday, but now this junk screen! I've always used 3440x1440 for my resolution (exactly what the screen has as max). I've been playing SWTOR since it came out, and this is the worst bug I've ever encountered!

Oh and reinstalling (twice) didn't help one bit!

usually occurs with nvidia when alt+tabbing away from the screen when loading

See this guide 

• Screen is displaying a solid color before or at the character select screen
  
           Press ALT + Enter first to switch to window mode and back to fullscreen otherwise

                  Go to C:\Program Files (x86)\Electronic Arts\BioWare\Star Wars-The Old Republic\swtor  and delete just the file called discachearena then start the launcher and login.

I am currently having this issue.  Only problem is when i go to that folder or do a search for that discachearena file i cant find it anywhere.  I have tried reinstalling the game on both digital download and on steam (worked for 1 day using steam) even tried switching from my D drive install to my C drive install and still getting the pink box every time i load.  Is there anything else i can do??

Unfortunately I don't have anything to help you.  I too tried to find the aforementioned file and was unable to locate it.  I have tried repeatedly talking to customer support and have yet to find an answer.  I am at the point of stopping my subscription and stopping playing SWTOR!  If you have anything else to try I'm game to try but I am out of options at this point.  All other games I have work properly.  

the diskcachearena file is in another folder called swtor once in the game folders , have you tried pressing alt + enter keys a few times ?

Play the game in fullscreen (window) mode the issue shouldnt occur