Forum Post: RE: Check of update source failed due to unexpected error 'Base64Decode returned false'.

Hello Kev/James Do you just have this one Update Manager? If so its possible to follow the below steps to re-create the private keys. 1. Open the Enterprise Console and remove 'Sophos' as a Source from the Update Manager configuration. 2. Hit OK on any warnings when saving the configuration. 3. Close the console and restart the Management service and SUM service. 4. Backup the private key in the registry keys found in HKEY_LOCAL_MACHINE/SOFTWARE/Wow6432Node/Sophos/EE/Managament Tools/Private 5. Delete all of the REG Binaries within Private. (they should look like BEGIN_SECURE_TICKET) 6. Open the console and configure the SUM again. Do let me know if this resolves the issue you are seeing.