_sans is not allowing?

Hey there I have set up some text buttons that drive from an xml file.
The font is set to something like (Universe 55) or some jit like that.

When I try to standardise the font to _sans it bugs out and the text fields become blank.

I have used this text setting many times before in an almost exact manner.

is there a publishing setting that is incompatible.

oh well time to try some options out.
cheers