Unable to open Illustrator app. Please help!

start at the top here - https://helpx.adobe.com/manage-account/kb/troubleshoot-creative-cloud-sign-out-sign-in.html

if that fails,

1. go to the bottom section : "Remove Adobe User and Adobe App Certificates" - https://helpx.adobe.com/in/download-install/kb/adobe-license-issues-keychain-credential-mgr.html and follow the steps.  

2. then uninstall the cc desktop app, https://helpx.adobe.com/creative-cloud/help/uninstall-creative-cloud-desktop-app.html

3. and reinstall the cc app install the cc desktop app by using the download links at page bottom here, https://helpx.adobe.com/in/download-install/kb/creative-cloud-desktop-app-download.html

in the future, to find the best place to post your message, use the list here, https://community.adobe.com/

p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post (like this one has already been moved) if it helps you get responses.

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