I'm stuck at a point I encrypted my data in Laravel application after that I updated my App key now when I'm trying to access my data I'm getting invalid MAC error how I can fix this
I think the way and sequence that you come to hit the error is crucial for the folks here to understand what had you did wrong, perhaps you need to elaborate more details, and also the error message.
But i would suggest that to figure out whether the issue is the App key issue corrupted or the encryption issue causing the application not functioning properly.
you may try to use your backup unencrypted version to regenerate your app key to give a try first.
If you still have your old key, you can add it as an environment variable named APP_PREVIOUS_KEYS, and Laravel will handle decryption and re-encryption gracefully.
This is a new feature of Laravel. Taylor explains how it works in this video.