There has been a major change between V15C1j and V15C1k in the way 12df stores and uses the value “Antennae Phase Center”.
In V15C1j and earlier version the value for “Antennae Phase Center” appeared on the Target Heights panel. This meant the value could be changes on the fly, and led to errors in field work.
So the decision was made to set it at the instrument setup panel and then not let it be changed during a survey.
12dF_GPS_PROFILES.4D was chosen as a logical place to save the value.
This means a file format change between V15C1j and C1k and later versions.
The 1st you will know of the change will be the warning message:
12df is literally asking you to open your user folder in Explorer, and rename the file.
I have just put a .j extension after mine, it is enough to stop 12d from reading the file.
Then the next time 12d Model starts you will have a new blank file. If you had a project open when renaming the file you will need to restart 12d Model, not just 12df.
When 12d restart you will see:
You now have a new blank file ready to have your values added.
The 5th field will contain the “Antennae phase Center” if needed.