What to consider when upgrading Mods?

[biocyberman]

Hi there,
Many times I want to use some modifications (mods) which were written for older versions of vbulletin. Problem is that the authors of these mod maybe too busy to upgrade their mod by themselves. So I want to install, test, debug and write additional code if necessary so that these mods can run well in current version of vbulletin, i.e vb 3.7.3. PL1 or vb 3.8. I guess those mods were written for vb before 3.6 will require more work. Nonetheless I would like to know what need to be considered when trying upgrading these mods. I am asking because I have been working with vbulletin for a while but my understanding about architecture differences of vbulletin versions is very limited. Welcome any comments suggestions and guidance :)

[Dismounted]

Most modifications written for vBulletin 3.5/3.6 will work on 3.7.

[Lynne]

Always read the releases for the new versions of vbulletin. They usually spell out if there is some change in the way something is done. For instance, the addition of the security token for 3.7 was a big deal for some mods. It effected all forms. So, if you know about the security token, then you know to go through any mod you may have installed and make sure this security token is present (sometimes you don't even have to do that, you just need to upgrade the modification).

[biocyberman]

@Dismounted, Lynne: Thanks a lot for your inputs :).
I also got impression that security token is the most common problem when upgrading mods. I can handle this thing. I will come back when any specific problems.