Interesting note, Tim. Thanks for the tip.
What, if any, error message is reported in the FMServer log when it tries to open the incompletely converted .fmp12 file?
If there isn't one, there ought to be, and it should be informative; something for the suggestion box. I do recall that FMS 7-11 is able to report back something like, "xxx must first be opened in FMPro"
-- Drew Tenenholz
Good to know, hopefully someone will benefit from the knowledge learned from your unfortunate frustration.