Hello SVK_Martin,
Thanks for reaching out to the Apple Support Communities. We understand you are experiencing some issues with an app being frozen on your Mac. We are happy to help provide some guidance.
To start, we want to make sure that the version of Adobe Acrobat Reader is compatible with your macOS version as well as your MacBook Air model. We would recommend reaching out to Adobe for guidance on ensuring that version you are trying to install is compatible with your MacBook Air.
You also mentioned that you aren't able to force quit on your Mac. How are you attempting to force quit the app? Are you using a keyboard shortcut or going to the Apple Menu () > Force Quit?
If an app freezes or quits unexpectedly on Mac
We hope this information helps.
Best Regards.