Origin not opening, and crashing after games close

Solution 1:

According to u/slayer_969 at https://www.reddit.com/r/origin/comments/as7v2r/origin_encountered_a_serious_problem_and_must/

Turned out to be related to downloads, meaning origin was opening normally and crashed when i tried to download or update a game. The solution was one of the two steps i done: 1- Uninstall Origin then install it again. When installing uncheck update games automatically. Then the client should open and not crash. Then go to Application settings > click on Diagnostics > toggle-on Download in Safe mode. Restart the client and try downloading or updating a game. It should work. 2- Port Forwarding. I forwarded ports that origin uses. Go to www.portforward.com they have all the information you need to do it.

I did both of these steps before retrying Origin so I don't know which fixed the issue for me. Good luck!