I have a PDF form using AcroForm that generates a "Don't know how to calculate the position for non-simple fonts" exception when calling setValue on a textbox field. After running it in a debugger, it appears the problem is that the font inside the AcroForm resources is named "Helv" but PDFBox gets "Helvetica" as the cosFontName on line 434 of PDAppearance.java. So then when it tries to get the font from the formResources on line 439 (formResources.getFonts().get( fontName ), it returns null because there is no "Helvetica" font, only "Helv". I changed the fontName variable's value to "Helv" in the debugger and that allowed setValue to complete without error.
Is this a problem with the form? I didn't see any way to fix it in Acrobat Pro's UI.