Illustrator und co. speichern Dateien versteckt ab.

Hi there,

Sorry about this trouble and the delayed response. When you save and open files across a network or from removable media, many variables affect application performance. We have a very limited support for server and network based environments. (https://helpx.adobe.com/in/illustrator/kb/illustrator-support-networks-removable-media.html), but from personal experience I would suggest you few things which you must check:

• Check if this is happening with your user account only or with multiple user accounts.
• If this is managed by your office IT, check if there is any antivirus or if there is any end point security or if there is any restriction imposed by your IT Team. Due to this sometimes server does not allow application to save but you are able to save outside the application. 
• This generally happens when network policies or Operating System is updated, check with your IT team for the same. 

Let us know if the issue is resolved or if it still persists.

Regards,

Srishti