The error messages generated by MASM components fall into three categories:
- Fatal errors. These indicate a severe problem that prevents the utility from completing its normal process. 
- Nonfatal errors. The utility may complete its process. If it does, its result is not likely to be the one you want. 
- Warnings. These messages indicate conditions that may prevent you from getting the results you want. 
All error messages take the following form:
Utility: Filename (Line) : [Error_type} (Code): Message_text
where:
- Utility 
 The program that sent the error message.
- Filename 
 The file that contains the error-generating condition.
- Line 
 The approximate line where the error condition exists.
- Error_type 
 Fatal Error, Error, or Warning.
- Code 
 The unique 5- or 6-digit error code.
- Message_text 
 A short and general description of the error condition.