So I have one of the typical 50 1.4s that have that focusing issue.
I took it apart and followed instructions online about 2 months ago to fix it and it has worked perfectly until yesterday.
I decided to take it apart and try to flatten out the metal again and did it twice, last night and this morning but it's still not working properly but that's the least of my concerns now.
After the 2nd time of taking it apart this morning, I was testing the focus and suddenly Error 01 showed.
Now the aperture blades are stuck at f/22. I've checked Google and tried to clean the contacts on the lens with an eraser but currently it's still stuck.
I click the DOF Preview button with the camera on (5DC) to to move the aperture blades but nothing is happening.
Overall, anyone have experienced with this? I don't know what to do but I know if I send it to Canon or take it to a shop it will cost as much as the lens so I don't think it's worth it.
Please let me know if you have any experience with this!
*I also put on another lens, my 35 f/2 and can confirm that it is not a problem with my 5DC since everything works perfectly