Custom key encryption is an additional level of security for each device on your account that requires a unique encryption key to be entered along with your account password when accessing your data. If your key isn't working, try the following:
Use the CrashPlan console
Sign in to the CrashPlan console and restore a file to be prompted for your custom key. You can try and enter the key as many times as needed.
Enter the key manually
If you are using copy/paste from a document, try entering the key manually. Some text editors can insert invisible characters that will cause a key to be entered incorrectly, even if it looks correct.
CrashPlan for Small Business support cannot assist with recovering custom keys. The keys are stored only on the local device and are never stored in the cloud. Technical support agents do not have access to your archive key and cannot recover it for you.