Updating an old file version from PDM

I open an out of date file from PDM, then I 'Get Latest' from within SWorks and this is when the message pops up. (I blanked out the filename myself). I think I understand the last line although it doesn't appear very good english. What I don't understand is that, given the three options, there is no way I can "lose the changes to version '17'".

Choosing 'Use Version from Vault' is the natural thing to do, it updates the currently open file as I would expect.

Choosing 'Save Open File as Copy' will make a copy of the currently open file, thereby protecting the integrity of the version in the vault (version 17).

'Cancel' - I end up using this option, closing down my model file and reopening the file but using 'Get Latest Version' before doing so. I do this because of the confusion this warning creates. How could it be possible for me to write over version 17 in the vault?

TIA

Maurice

SolidworksSolidworks Pdm enterprise Pdm