when i get a software to actualy download, and I try to open it, it comes up with an error as well, i.e. such and such a python not detected, no data detected
It sounds like you're close, you need to install all the packages reported by the error.
I went to DivX site and could not find anything for linux, only Mac & Windows. Can you provide a link to the download page you're getting this from?
If masonm is correct and you are using an RPM distribution, the name of the file you are downloading/installing should either end in .rpm or .tar. The .rpm can be installed by the OS using a utility called RPM which does not take care of installing dependencies (other packages that need to be installed before this one). Fedora based distributions are probably all still using yum as the default package manager that will take care of installing dependencies providing the package you are trying to install is in your Linux distribution's repositories.
Chances are DivX is not in the repositories which is why it's using RPM rather than YUM.
If you have an application that allows you to see all packages/software available for installation (as most do), use it to install those missing dependencies.
I'm not sure what the issue is with the error you're getting when trying to access the help in settings, but I would not go playing with settings just yet, nor would I suggest jumping the gun and doing a re-installation. Try installing those packages mentioned in the "install" error first, then try to install the DivX package.
And if you still run into issues, don't forget to copy and paste the link in the URL field of your web browser here when you are on the download page where you're getting this package so we can see what you're trying to install.