Clicking on the text box in the tab doesn't work either - nothing is in that box, and when I move the box to see what's behind it, I can't get to anything I can edit.
What "text box" is that? A field on one of your tab panels and not shown in your screen shot?
In your screen shot, the tab lables appear to be the same font, but the first and last are a different color. Is this the issue you are describing here?
If I click on the tab, the little squares that surround a text box appear, but nothing is in them.
The fonts are definitely not the same - note the two different capital "C's".
Still not clear what you mean by "text box".
By any chance where text objects placed on top of your tab labels instead of entering the label text into the tab control set up?
What do you see when you double click the tab control to open the tab control set up dialog?
Sorry, I've been out of town for a couple of weeks.
I thought that the headers in the tab control were editable text boxes, but I now realize they are not.
So now I really don't understand why the different tabs are different fonts, and I assume the cause is the updating from FMP11 to 12.
When I double click the tab control, I see the names of the tabs as displayed in my screen shot, so that's fine.
While (in Inspector - in "Appearance", "Text") the font size/type of the tab control appears to be editable (not grayed out), changing that font has NO effect on any but the first tab.
Found the answer in another forum post, last April...Tab control label scrambled after conversion from FMP 11 to 12.
Worked like a charm...:)