I came across a web page a long time ago that lists all(?) of the cryptic WSUS error codes, such as 0x0000041D. This is extremely helpful when troubleshooting WSUS logs and WindowsUpdate.log files. I've found that it's helpful for lots of other Microsoft products, as well! I saved it as a portable MHT file that you can download.
If I could remember where I found this, I would gladly give them credit.
Please to enjoy. WSUS Error Codes