You may run into situations where your 4D application (Standalone, Client, Server) fails to start up properly. Furthermore you may find that none of your 4D code has been executed before 4D fails to start. In this instance a faulty plug-in is the most likely cause of the startup problem. Here is one way to troubleshoot this kind of problem:

• Place a call to the TRACE command as the first line in the On Startup method (or On Server Startup in the case of 4D Server).
  
• Check to see if the user you will log in with has a startup method. If so place a call to TRACE in that method as well.
  
• Launch a copy of your database without any plug-ins.
  

The database may not be functional without the plug-ins but in this case this is not relevant since all you are trying to do is get far enough in the 4D startup sequence to the point where your own 4D code starts executing. If you can connect to your database and see the TRACE window then one of your plug-ins was causing 4D to crash. You can then proceed to add the plug-ins back in, one at a time, until you find the offending one (although in some cases a combination of them may be at fault so the testing may become more complex).