Where does Windows Server Backup store its "templates"?

I have a malfunctioning Windows Server Backup instance on WS2012R2, it has a weird but stable behavior - it starts up, if it succeeded last time, it fails with 0x8007007b ("Syntax error in file or dir name, or volume label"), if it failed last time, it succeeds instead, producing a correct backup of selected files and folders. I have run it with procmon at its side, and discovered that it goes for "D:\TEMP" with a weird request that throws this exception - the problem is, "D:\TEMP" is NOT in the backup plan, and to my knowledge it was never in there. I am unable to remedy the error by altering the selection and then saving it back, I am unable to remedy the error by re-creating the backup task in its entirety because stupid wbadmin would drop existing backup data off the media (), and it's a production solution of a client to boot. Therefore I need to find out where does WSBackup store its configuration data.

The only valid identifier for the data is "templateId" written in the scheduled task and passed to "wbadmin start backup". There is no GUID in the registry, there is no mention of -templateId parameter in the wbadmin help, either in MS or locally, and there seems to be no file with such a name across local filesystem. So, where should I find the Windows Server Backup template data?

the -templateId option is an internal option avaliable only for a scheduled backup configuration done from backup clients (wbadmin.exe, wbadmin.msc). If you want to have an adhoc backup command for batch scripts, use the commands avaliable from "wbadmin.exe /?"

From a Microsoft employee post here. In polite, normal English, that's saying they don't expose that option publicly.

Your best solution is to delete whatever backup jobs you have in there, and recreate them. I'd suggest a relatively simple PowerShell script to interface with the Windows Backup feature, rather than the GUI. The technet reference guide for the Windows Server Backup PowerShell cmdlets can be located here.