Sorry to hear about that. I would request you to share a few more details like:
OS & the exact version of Illustrator installed.
Does it get stuck at launch or while working on a specific file?
Please share a screenshot of the error if you are getting any.
When did this start happening? Are there any recent changes made to your system? For example, any antivirus, system updates, plugins, or web extensions installed recently.
Where are your files saved (Network Drive/ System HDD/ Shared Folder on System/ External HDD)?
Does resetting Illustrator Preferences (https://helpx.adobe.com/illustrator/using/setting-preferences.html) help to resolve the issue? Disclaimer: Please note that resetting preferences will remove all the custom settings, and Illustrator will launch with default settings. You can also take a backup of the folders in case you want to. Location is mentioned in the article.
We are here to help. We just need more information.