Thanks - is there a manual I can download to stop me asking dumb questions?

Thanks - all good now

I am a disgruntled TeamViewer user - I was told I had to buy a licence even though I am not using it in a commercial way.
Love this product.
One nice-to-have would be the ability to rename the connections so that instead of "999999999 (Laptop-XXXXXX)" to a more user friendly "Wifes_Laptop".

Based on your comment above, when I create a new key and copy and paste it to a file (instead of using the save to a file option) the key is now valid and can be used to gain access to the object computer.
After that I found another issue. The object computer is a recent build and was configured with a Microsoft account and PIN to sign in. Remote access was being rejected with invalid credentials. In desperation, I changed the login to a local account and a traditional password - the remote access is now working.
Thanks for your help, this issue is now resolved in my case.

Here is the key file also - I will now change the key on the Target computer.

I will be away for about 4 days so I won't be able to respond to any thoughts / actions till then.

As mentioned in my post, I have also used the "Read it from file" option as well with the same result on several different key files generated by the Target computer.
Thanks for your quick reply.

I have just installed the software on 3 local Windows 10 computers. Two of them have unattended access enabled and I can access one OK. When accessing the other one I keep getting the error "Public key must be a base64 string". This happens when I copy and paste or Read it from the file. I have ensured there are no training or starting blanks in the key and the previous key has been erased before pasting. I have created different keys on the remote computer and each time I still get the error.

Please advise how this can be resolved.