| ERROR | unknown format specifier in file name string |
| CAUSE | A format specifier is a percent sign followed by a character. The percent sign and character are replaced by a value depending on the character. This error occurs when the character following the percent sign is not defined to have a value. |
| ACTION | See the documentation for information on valid format specifiers. If the file to be opened needs to have a percent sign in its name then use two pecent signs. They will get replaces by a single percent sign in the resulting file name. |