Windows 10 'Codebook Locked Message' when logging on to PC

I’m running Windows 10 and have a strange message that appears intermittently when logging on to my PC.
After entering my Windows username/password and before the main desktop window appears, I get a message popping up informimg me that ‘Codebook is Locked’.
I dont expect to see this as I am careful to close the app before logging out and only expect to see this after I close it normally or if the app times out.
Any idea whats causing this?
My CB version is
Thanks in advance

Hi @RayJay,

Thank you for reaching out, I have just sent you a DM containing the link to the latest Codebook for Windows installer. It appears your install is rather old as our current version on Windows is 4.5.13. Would you try updating to see if that addresses the issue? Thanks!

Hi Nick
Thanks for your fast reply.
I have installed the latest Codebook release and works fine.
I will monitor for the error over the next week and keep the post updated.
So far no issues.
Thanks again - Ray