This error means that the is a redistributable component that is not being installed in your computer while installing RiftGG. The reason can be because you already had one installed but is not updated.
We have an executable that you can use to install it manually.
Access to C:\Program Files (x86)\RiftGG\bin
Once you have installed the Redistributable, try to install again RiftGG.
If this still does not solve the issue you might have to delete yours from your computer. Before you do, have in mind that this might cause that some other program will stop working. The name of the Redistributable you would have to delete, depending on your computer, can be any of the following ones:
Microsoft Visual C++ 2015 Redistributable (x86)
Microsoft Visual C++ 2017 Redistributable (x86)
Once you delete it, please try to install RiftGG again.