Answer:
The *.dll and *.tlb files were probably not updated correctly on your computer. Please proceed as follows:
- Rename the following folders in Dlubal.bak: C:\Program Files (x86)\Common Files\Dlubal; C:\Program Files\Common Files\Dlubal
- Reinstall RSTAB.
- Move the files from the newly created Dlubal folders to the respective Dlubal.bak folders (overwrite all).
- Rename the Dlubal.bak folder to Dlubal.