Hi @Konstantina
First of all, let me welcome you to the community! Feel free to Introduce yourself 🙆 to everyone if you want to 
As for the GH message, I’ve encountered this before but only on a specific case (let’s hope this is the problem on your side too)
Possible cause of the problem
I’ve only found my self getting this error when:
- I had the Grasshopper connector installed
- I had the Rhino connector installed
- The Rhino connector is older than the Grasshopper one (i.e. Rhino version is 2.3.x and Grasshopper is 2.4.x)
Would you happen to have the Rhino connector also installed? If so, what version? Does uninstalling the Rhino connector fix the issue?
A different possible cause
We’ve noticed sometimes the installer won’t complain about “open applications you must close before updating”, causing the installation to not fully overwrite the files.
If the first suggestion above doesn’t work, could you try:
- Uninstalling all Rhino related connectors (rhino + grasshopper)
- Restarting your computer (to ensure no open programs are lurking in the background)
- Install the Grasshopper connector (and Rhino one if you need it)