Photoshop CS6 I can't use my old version anymore

[HanaToKirara]

I have a student and teacher edition of Photoshop CS6 that I have purchased at a school store back in 2013. I have been using it on this computer for a good amount of time and I have payed the full price for it. However, recently I needed to download Cloud and purchase a plan for a class with other programs including the latest version of Photoshop. I did not expect it to affect my old Photoshop. However I had to cancel the plan and it affected my old version and I can't open it without it being renewed. I tried to validate it because I still have the card with the download code. However it does not accept it and my Photoshop appears as a trial. It had nothing to do with the plan and I absolutely need it. Please help me.

[Peru Bob · Accepted solution]

See if this helps:

Adobe Creative Suite 6 applications unexpectedly revert to trial mode

[HanaToKirara]

Thank you. I got support and fixed it. It was basically just what you said.

[HanaToKirara]

I solved the issue. Thanks for the support.

[Peru Bob]

You're welcome.