Bobby,
Not sure what you mean by “will not let me import into AE.”
You don’t import the plugin into AE, you put the plugin files (those ending in .plugin on Mac and .aex on Windows) into AE’s plugin folder.
Nor does this plugin give you a different “import” option within AE.
After you put the Twixtor plugin into the plugins menu, and restart AE, the plugin then shows up in the Effect menu (under the RE:Vision Plug-ins submenu).
You put some footage into a comp, then apply Twixtor (using the menu item Effect->RE:Vision Plug-ins->Twixtor 4.5.
You are going to want to set the input settings of Twixtor to have an input frame rate of 29.97 and the appropriate field order (probably Lower Field First). Then you can simply set the speed to whatever you like (for a 4x slowmo, set the speed to 25%). Of course, if you are extending the footage you’ll need to read this: https://www.revisionfx.com/auxdocs/ExtendDuration.htm
Please read the manual that is put on your disk with the plugins upon installation. It will explain quite a few non-obvious things! Then, when you are done with that, you can go to our tutorials page for more help ( https://www.revisionfx.com/auxdocs/ExtendDuration.htm )
Pete Litwinowicz