HTML Error Pages

The first three classes of error (query syntax referring to .idq files only, .idq syntax, and .htx syntax) always generate an HTML error page. The page returned for each class of error is specified in the Language-Specific Registry Settings. Registry keys are under the following path:

HKEY_LOCAL_MACHINE\SYSTEM
 \SYSTEM 
  \CurrentControlSet 
   \Control 
    \ContentIndex
     \Language
      \<language>

The keys are:

ISAPIHTXErrorFile, ISAPIIDQErrorFile, and ISAPIRestrictionErrorFile: Configures .htx errors, .idq (and .ida) errors, and query syntax errors.
ISAPIDefaultErrorFile: Reports other errors.

These pages are standard, completely customizable .htx pages. The variable CiErrorMessage contains a localized string describing the specific error, and CiErrorNumber contains the error code.