WHY : do I have the error message that my .xhb file in an invalid file ?

File are compatible with different platform but with higher or equal version of the software.

The internal structure format of HomeBank file may changes when adding new features, and so, it is no more possible to open it with lower version of HomeBank, at least WITHOUT LOOSING DATA introduced with new features. So to AVOID LOOSING DATA a such restriction is part of the software.

A file version change is always mentioned in the Change Log file.

The solution is to always use the latest version, and if you use both MS Windows and GNU/Linux, to have the same HomeBank version on the 2 operating systems.