It is a known restriction that DIAdem, and DataFinder coerce spaces to underscores when searching for property names on TDMS files. The Excel Add-in does something similar.
But the TDMS file structure and API apparently supports reading and writing properties with spaces in them. So my question is why does DIAdem and DataFinder not support spaces in the name of properties? This limitation must exist for a reason since if it were a simple fix it probably would have been taken care of years ago, so I'm not asking for this functionality to change just curious.