Stunnel Errors

I have a web server and the fellow who put my Certificate on used stunnel. But stunnel keeps causing an error and shutting down...which stops the ability for a secure connection (required to make a reservation at the facility). Any ideas of what I should be looking for to figure whay it shuts down all the time?

Solution ; - Its very weird error.  Please try this :
Go to task manager , locate the service for stunnel.exe , right click on it and set the affinity to only one CPU (either cpu 0 or cpu1)