I know you said that the files on both servers are encrypted. But this error
The source file is not encrypted. Source: /opt/FileMaker/FileMaker Server/Data/Databases/file.fmp12
is pretty clear. It is saying that the file in your Databases folder is not encrypted.
That error comes from the Data Migration Tool, not OttoFMS. OttoFMS is using the Data Migration Tool to perform the migration and that tool is reporting that the source file is not encrypted.
So the first thing to check is that file. Are you absolutely sure it is Encrypted? Can you download the file and try to open it. Does it ask for an encryption key? Can you try the migration without an an encryption key?
OttoDeploy should let you proceed without an EAR field filed out. So if this doesn’t seem to be working for you could you send us a video of what you are seeing? That might help us figure out what is happening in your case.
That might because currently you can’t migrate files that don’t have the same encryption state. They most both be encrypted or both be unencrypted. That might be what OttoDeploy is detecting. But if so, that message could be better.
Did you know that you encrypt and decrypt files right from the OttoFMS console?