Topics created by Mr. Bill

^^^ What notareal says is correct; you could do it, but I can't see any gain.

As explained the lone RB/RBS files are effectively unchanged by the newer version, but more complex toolsets come in ZIP archives that need extracting properly into the Plugins folder keeping subfolder structures intact - this has been the source of many user misunderstandings and errors. Recent changes to SketchUp v8 have introduced a special RBZ archive file format - basically it's a ZIP archive with a renamed file-type extension - that SketchUp recognizes and auto-installs when you click on the appropriate button...

Even better than that... thomthom has made a 'Simple Plugins Installer' that works in these more recent versions of SketchUp v8.
You can download it from the 'Plugins Index' here.
Once you have that installed - and as it's an RBZ archive you can easily installed it from the Preferences > Extensions button +restart - it can then be used from its new Plugins menu submenu...
It allows you to browse to and auto-install/load tools/extensions from RBZ & ZIP archives AND also install individual tool's from RB & RBS files: auto-extracting them as necessary and placing them and any subfolders of files etc correctly into your Plugins folder[ without you worrying that you might have mis-installed something or have chosen the wrong folder etc...

EDIT: PS:
The issue with the TT Lib seems that you have not extracted/insatlled it properly.
I suspect that the subfolder+file that is needed to be directly inside Plugins are actually inside another subfolder of that same name, made when you unzipped things...
Move things out of this containing folder into Plugins, remembering to keep all of the Lib sub-subfolder's files intact within it... OR much more safely why not remove the whole lot and restart - using the archive itself - with the 'Simple Installer' as explained above 😒

If you in tight budged, then there are two free renderer that I would look on; Kerkythea and LuxRender. Kerkythea has a commercial sister Twilight (same engine, but streamlined UI. Limited to 32-bit memory space and SU polygon handling capabilities). LuxRender has a fairly new exporter so may need some maturity, but worth look on (sorry no deeper experience with it).
In landscaping one may often need displacement or instanced high poly threes or other entourage. Thea Render can do both, with near unlimited resolution (up to available ram, with Thea 64bit), in reasonable cost. Vue Infinite may be hard to beat with it's EcoSystem, but it may be out of budget.
There are quite many topics on rendering programs, many has a favorite one, but best to test those that look interesting. Also, different tasks may give a need to have multiple renderers available.

@arklandesign said:

The trees on Page 8 is from Formfonts named "gentle tree".

That is exactly what i was looking for. To be specific it was "generic tree 7". Thank you all for the input though, this has been the fastest a forum like this has ever turned around an answer for me. Actually many helpful answers. Thanks again.