We want small memory dumps. Please configure your computer for Small Memory Dumps.
The code you listed means what the error message said
It cannot find the source to repair from. What installation media do you have to install Windows 10?
0x800F081F The source files could not be found.
Use the "Source" option to specify the location of the files that are required to restore the feature. For more information on specifying a source location, see Configure a Windows Repair Source.
The DISM log file can be found at C:\Windows\Logs\DISM\dism.log
0x800F081F - CBS_E_SOURCE_MISSING
Error code: 0x800F081F
I thought you had determined the problem was the USB dongle.