As you mentioned that while working on Illustrator it says Activation failed, please see the link for help:
Hope this helps!
Feel free to reach out to us for more questions.
No it doesn't help, next suggestion please!
Could you please specify what all steps have you tried?
Did you try logging out and then logging back in?
Kindly Rename the OOBE to OOBE.old and then try to sign in:
Windows C: \ users\ User account \ App data \ local \ adobe \oobe
MAC: Go / Go to Folder / Application support / Adobe / oobe
Let us know if that helps.