You opened one of your drawings, and one or more of your fonts have been replaced by the font Simplex.shx.
You might see text similar to the following in the Command line:
Substituting [simplex.shx] for [archquik.shx]
Substituting [simplex.shx] for [ZapfHumnst BT]
The fonts that have been replaced are likely custom fonts and/or fonts that aren't installed in your computer font library. AutoCAD automatically replaces these fonts with Simplex.shx.
1. Check the Command line to determine which fonts have been replaced with Simplex.shx.
2. Install the missing fonts on your computer.
- Installing SHX fonts? Place them in the folder C:\Program Files\AutocAD 20XX\Fonts (where 20XX represents your year version of AutoCAD or F/X CAD).
- Installing TrueType fonts (TTF)? Place them in the folder C:/Windows/Fonts.
3. Close and reopen CAD. Your fonts should now come in correctly.