Catalog error in MDT with ADK 1903
A little tip from me to you!
If you get an Catalog error in Microsoft Deployment Toolkit when
trying to Edit Unattended.xml or when you trying to Update a Deployment Share
and MDT needs to create a catalog file. You probably have Windows ADK 1903 installed
and you have an x64 bit Operating system running MDT.
Microsoft have released a fix for this issue and It can be found at the ADK Install page.
The fix did not work for me so I tried to uninstall the ADK + PE add-on.
And then installed the 1809 ADK instead.
Now I can create new images again and MDT creates catalog files without errors.
You can read more about the problem and how to see If you have the fix for ADK 1903 installed or not here.