No thanks to Adobe, even after numerous complaints going all the way back to Creative Suite 1, if you have a bad font on your system, you may have issues saving as an .ai in Illustrator. You’ll get the dreaded “an unknown error has occured”.
If you disable PDF compatibility, it will save, but that’s not good enough!
You may also have a problem in Photoshop, where whenever you try and type on the canvas, it says an unknown error has occured in the font rendering engine or something to that effect. Again, similar error, stupid Adobe.
Turns out if you go to your fonts directory, hit CTRL-A to select all items, then go to the file menu, “copy fonts to” and select a folder on your desktop. Copy all the fonts to this folder, wait till it’s done.
Now go ahead and download a free trial of Font Agent for Windows. And let it analyze all your fonts. It will tell you which fonts are bad.
Go back to your windows font directory, delete the bad fonts. Restart Photoshop, or illustrator, and you should be able to save again.
This comes after probably 6 hours of trying different fixes with the transparancy settings, the font cache, font .lst files, adobe presets deleting, app setttings deleting, etc this is the only thing that fixed it.
Maybe it’d be nice if Adobe included a little “verify my fonts” checkbox and alerted us to bad fonts. That’d probably be too easy though.