I can’t tell from your profile what system you’re using, so I gave links for Mac and Windows. With Mac it’s a disk image, and you drag the SketchUp 2021 folder to Applications. For Windows it’s an installer EXE.
If you have a Classic license, activating 2021 will make it be your active version, and I would have to change something if you needed to go back to activating 2020 or 2019. You could run 2021 as a 30 day trial too, and wait until later to add your classic license.
If you have a Classic license, neither 2018 or 2021 need you to sign in to use most features. Both 2018 and 2021 require you to sign in to use some features. The sign in on 2018 requires that you have a Trimble ID. The sign in on 2021 lets you sign in with Google or Apple instead.
There are restrictions if you compare Classic versus subscription, but not if you are using a Classic license in both cases.
But that doesn’t matter. If 2018 is working ok, then all is good.
There was a PowerPC version of SketchUp? Didn’t think it was ever on pre X86 Macs.
To refresh my memory, I just checked my old Titanium PowerBook (1Ghz PowerPC G4 Processor): It had SketchUp 3,4,and 5 installed on it.
There wasn’t an OS9 version, maybe that’s what I was remembering 
A Classic mistake, you could say…
I think that’s right. On the other hand, BeamMac/FrameMac never had an OSX version, which is one of the reasons I kept the Titanium PowerBook around and pulled it out from time to time.
Indeed.
Right On danbetteridge …
And I’d add, FIX LayOut for Mac into a robust, fast performing package that can be a worthy partner to SketchUp (instead of the sluggish, flawed second cousin it is today!).
I’m a bit worried that just as LayOut seems to have taken a back seat priority for current improvements, Trimble will again focus on SketchUp performance, and push LayOut performance to the back when accommodating the new M1 generation Apple chips!
Huh, TIL (today I learned)
interesting thought…probably going to be a trash barge full of not even old Apple products looking for new owners.
Shhhhhh… 
What are these fixes and new issues you speak of? The only thing I see of value is the Layer Groups, but like @trampy, I use a text/number system to order layers so it’s kind of a wash. Quick on/off of entire groups is attractive, but not a reason to upgrade since the opposing force of this last update to the Layout frustrations has me skeptical about the importance of Layout to Trimble.
I think I’m sufficiently convinced of the M1 breakthough that I will wait two years to upgrade anything I have, both hardware and software, so I can watch the development cycle that Apple works thru and also how Trimble chooses to handle Layout: perhaps, as @Beamer2 said, it will get a promotion from the kids table and become a full AND unparalleled partner to Sketchup, seated at it’s right hand…as it were…and all while doing dances on what by then might be M3?
I know Apple is going to launch fireworks…hoping Trimble use the M1 as a reason to start dumping some money into fireworks too.
The most useful fix was that when opening a LayOut file that is missing linked SketchUp models, the embedded versions are used. In 2020.2 it would crash LayOut.
The biggest new issue is the one I talked about here:
We can’t forget that you cant print from the 2020.2 for Windows. It will offset to the lower right corner.
Interesting…I have never seen either of those issues. Sketchup, for the most part, is stable on my machine. It does splat at times but that is due to an ongoing issue with my MBP and eGPU that doesn’t have anything to do with Sketchup.
At least that’s some good news…don’t have ALL the issues.
And since I have posted a bit the last few weeks and tend towards negative comments I have to say this. There is no comparable platform to Sketchup and Layout. As much as I moan about the issues, the intuitive nature of both platforms is beyond compare. I have been updating my title block templates the last few days and when I think back to the days of doing that same work in AutoCAD, I shudder a little.
Sketchup Team…keep after it!
Solidworks is powerful and there are tools that Sketchup can’t compete with. However Sketchup is so intuitive that I can train people quickly and most of those tools that Solidworks have are not useful for what we do. I am the only one trained on Solidworks in the office and I use it for sheet metal and when vendors can more readily use that file type but most of our everyday drawing is Sketchup. It is so versatile. I wish Layout was less problematic.
I think everyone is bagging out Layout. Credit where credit’s due. It’s a great programme and streamlines my workflow considerably.
… how Trimble chooses to handle Layout: perhaps, as @Beamer2 said, it will get a promotion from the kids table and become a full AND unparalleled partner to Sketchup.
… hoping Trimble (will) use the (Apple) M1 processor as a reason to start dumping some money into (LayOut) fireworks too.
Right On @KeithBrooks!
I like the “Kids Table” reference, that feels about right!
Maybe if Trimble could just step up to a “LayOut Pro” level program, we could be happy?