How to tell if you have a bug:

Can you repeat the problem? No: Congratulations! it's solved! (Well, you might as well -call- it solved if you don't get it anymore. Even if all you did was reload.)

If the problem can be repeated: do you have the latest version? And all the other required programs?  If not, Get them. (There is a handy FAQ here telling you what and where they all are.)

OK, so the problem can be repeated on your computer; you have all the required assets; and your installation is up to date. Can the problem be repeated on a different computer? No: It is objecting to your setup. Every setup is unique, and SimPe can't be guaranteed to cover them all. This is a problem, but probably not a bug. You need to be asking how to fix the setup.

Have other people reported the problem? This requires one or more forum searches with relevant keywords. If the problem has already been reported, it may have already been solved in one (or more) of the threads. 

Have you asked anywhere else? You should also try asking in the appropriate modding forum at ModTheSims, since there are more people there who can help. You will get as many people in one hour there as you get in one week here.

Do you have an error message? Error messages are not the sign of a bug at all, they are a sign SimPe has correctly spotted an anomaly or something it can't handle in the data. This usually suggests that the problem is known or anticipated, and the problem is quite likely to be in your project, not SimPe.

Does it really need to be fixed, or can you work around it? An example that I was guilty of was when I was having trouble getting SimPe to stop freezing up every time I tried to do something on either the old computer or the new one after re-installing the game. I spent a few hours trying to run a system check before I noticed that the file tables were showing that I had EPs and SPs that I didn't. I manually unchecked the boxes for the ones I didn't have, cleared the cache, restarted SimPe, and had no problems. I reported it as a bug, but it shouldn't have been. I had already managed to find a work-around.

If it really is a bug, they need to know a few things.

1. The details of the error report, assuming there was one. (Click the "Details" link, then enlarge the results so that you can actually see them. Then copy/paste or take a screenshot of it)
2. How to make the bug happen for themselves. (This would be the same thing you did to reproduce the bug.)
3. What you were expecting to see happen. You may think that is rather obvious, but the development team has dwindled a bit... If you ask any of them if they ever use ALL of the available options, I doubt any of them would say they have.   Also, "I tried to import a mesh, but it looks like this!" may have everybody agreeing that you have an odd looking mesh, but without knowing what it is supposed to look like even people who regularly import meshes won't know what the problem is.