Error 306

Did you recently upgrade your computer?

Which Win operating system do you have?  Go to Win search and type winver. Run the command.

Make sure your computer meets the minimum CPU & GPU requirements. Most Creative Cloud apps work on:

• Windows 10 versions 21H1, 20H2, 2004, and 1909 (LTSB branches are not supported;
• macOS 12 (Monterey), macOS 11 (Big Sur), macOS 10.16 or 10.15 (Catalina)

- https://helpx.adobe.com/creative-cloud/system-requirements.html

Windows 11 KNOWN ISSUES:

https://helpx.adobe.com/download-install/kb/windows-11.html

Please take a look here: Gelöst: ERROR CODE 306 - Adobe Support Community - 12557824

If this doesn't help please Consider including the following in your question:
Adobe product and version number
Operating system and version number
The full text of any error message (s)
What you were doing when the problem occurred
Screenshots of the problem
Computer hardware, such as CPU; GPU; the amount of RAM; etc

Thanks. The above info will help to solve your problem.