Issue
If Tiling+ exits with an error when creating an Assembly Guide, check if the page selection is not empty (as it should show page sizes like A4, LetterUs, etc.):
If it's empty then Tiling+ will crash when creating the Assembly Guide.
Problem
Page presets were removed.
Solution
Go to the Main tab of the Page Setup (within the print module/driver). Then, check to Template section and, if this is empty too, add a page size (like A4 or LetterUs):