Welcome to the forum.
Please when you have issues with blenderseed then add as much information as possible. Especially which version of the plugin you tried to install. The blender plugin is in constant development with frequent changes and it helps us to track problems. The latest release version can always be downloaded from https://github.com/appleseedhq/blenderseed/releases
The first error message seems to be some incompatibility issue. There is an Assertion Error after registration of the Radeon Pro Render plugin.
Maybe you make a clean install of Blender without additional plugins and then try to install blenderseed and see if the problem persists. If it’s a genuine bug, the main developer, @Jonathan_Dent will be thankful for the report.
I second Mango’s suggestion to disable ProRender. I’ve never seen that error before.
I can’t even install blenderseed. Look at the screenshot that I’ve included. Notice under “Prefences:” there is no “Appleseed Binary Directory” but something that says “Log Level:”. I did exactly as described (in the many conflicting installation manuals) & that is 1) Unzip Appleseed.studio any place (it doesn’t matter) 2) User Preferences/ double-click on zip file of blenderseed etc… but when I go to choose the binary directory I have “Log Level”. I have to say that so far my experience with Appleseed has not been so “user friendly” or pleasant. The version is “blenderseed-1.0.0-beta-win64”. I’m running Windows 8.1 & Blender 2.79. & BTW one of your installation instructions doesn’t mention installing the .exe appleseed.studio first.
Welcome to our forum!
I’m sorry you had troubles installing blenderseed.
The installation of newer blenderseed releases work the same way like other Blender plugins.
The blenderseed plugin is self-contained and includes all required appleseed-core binaries. There is no need to install additionally either appleseed-core or appleseed.studio.
In the link given in the 2nd message above under the paragraph Installation is a clear step-by-step instruction:
In the official blenderseed documentation there is a more detailed chapter about blenderseed installation, additionally describing manual installation or download directly from the GitHub master branch:
If you like to test the newest updates to blenderseed 2.79b you can download
a developer build from here: blenderseed-1.1.0-dev-Win64.
It has many improvements, most notably much faster mesh export, but as any developer build it is considered to be alpha status.