I'm guessing you are using the MacOS app. If so then you can try the following:

Terminal command

please try the following to fix the problem:

• open the Terminal app
• You can find it via Spotlight search, the magnifying glass in the top right corner (just type Terminal)
• Copy and paste the following command:
   

defaults delete de.ninoxdb.ninox-mac.Ninox
 

• then you can execute the command by pressing enter