TWebUpdate Error Codes

How do I find out what the error codes shown in the WUPDate.log mean? For example:

18/03/2021 17:21:22 : [915] Download : (Status:3) (Error:0)
18/03/2021 17:38:33 : [946] Cannot download update file : (Status:2) (Error:9)

The error codes shown in the TWebUpdate Developers Guide are all 12XXX 5 digit codes.

This is the value of the GetLastError call performed to get the Windows error code for the last failing operation.
The result codes can be found here: