I'm running WHM 11.28.13. I'm missing some images and CSS files in the WHM backend. The cause of this is that 'cPanel_magic_revision_1281697507' is part of the file path. I've run upcp --force but it didn't solve it. Any ideas?
What url are you using to access WHM? The magic_revision part is caching for images and style sheets, so you are correct there that it can impact those items due to the caching, but it normally occurs when using the proxy feature like whm.domain.com or cpanel.domain.com, so knowing the url you are using would be a start.
Next, when you access the area and are missing those items, could you tail the cPanel error log:
I've checked the error log and I see nothing there related to the login. Fortunately, after the daily upcp it now works. I've experienced this before, so it may occur again. I'll try and see what more information I can get then.