When there is an error in the analysis, Mplus often reports the number of the parameter that is causing the problem (ex: "PROBLEM INVOLVING PARAMETER 28"). How do I know which parameter corresponds to the number?
If you get a non-identification message, you should get TECH1 automatically if you are using the most recent version of Mplus. If you don't, you should send the output and your license number to email@example.com.
Go to the beginning of TECH1 and use the Find function to find the parameter number that you want. The remedy depends on the situation. If it is not clear to you, send your output and license number to firstname.lastname@example.org.