Start by checking with the plugin vendor to find out if you need an update
On what computer operating system is your Premiere Elements 10 running?
What is your Elements program - Photoshop Elements 10 or Premiere Elements 10? For now, I will assume Premiere Elements 10 Windows.
Specifically to what location did you install these plug-ins?
Please give me an example of one that will not install in 13, including to where you installed it.
I am not thinking manufacturer plug-in update, rather...
a. You trying to install the plug-in in the wrong location for version 13
b. The plug-in is not supported by version 13
c. The plug-in is appearing within the 13 project at a different location than in 10.
Thx everyone for your help. I closed Elements 13 then I downloaded the latest version of my plugin and Elements picked it up and upon install it now shows up as a plugin in Elements. I'll do this now with my other missing plugins. So problem solved. Thx again!
Great news. Great job in sorting through the details to find the path to getting those plug-ins to install and work for you.