@MAMATHA Adiraju The error message you’re seeing usually means there’s a mismatch or corruption in the encryption key used during token decryption. In Pega or similar systems, this can happen if the encryption key used to encrypt the token (or secret) doesn't match the one currently configured for decryption often caused by changes in key store configuration or corrupted secrets. To resolve it, first check if the key used for encryption/decryption is correctly configured in the key store or keystore file. If your application was recently migrated or restored, ensure that the correct encryption keys were imported or retained. Also, verify that the encrypted data wasn’t modified or truncated. If you're using Pega, recheck the authentication profile and associated keystore instance. Re-uploading or re-generating the client secret may help if the current one is corrupted or incompatible.