The second option is to manually integrate the already existing material libraries from either a previous version of the program that exists on your computer or another computer where the program is installed.
The following files located under C:\ProgramData\Dlubal\SHAPE-THIN\General Data from the existing version can be copied into the version with the missing material database.
General material library: 'Materialien.dbd'
User-defined material library: 'Materialien_User.dbd'