Why can't I sometimes save my file with AnyRail 6 using the same filename?

[David]

If you open a file in AnyRail 6, make some changes, and then 'Save', it might be that you get a warning that you have to save using another filename.

This happens whenever you've opened a file from an older version of AnyRail, while you don't have a license for AnyRail 6.

If saving using the same name would be allowed in this case, you would overwrite your old plan. The plan can then no longer be opened with your older, possibly licensed, version of AnyRail.

So you can still save the files, but you have to use 'Save as', and choose another name (or folder).