# -c:

When the "-c:" option is turned ON, the match of the font written in the dvi file to the font actually loaded is examined by using the checksum data (Property Sheets->[Font2]). This parameter takes a value ON or OFF.
If there is no match, a message like
check sum doesn't match in Font 35:
is displayed.
The number after "Font" is the font number in the dvi file (cf. Information display -> Font Information).
This error means that the tfm file used by TeX does not match the data in the loaded font that was actually loaded. This error occurs when the versions of the two files are not the same.