Unable to hide/unhide objects in Pro 2021 after hours of using the program

My lovely partner regularly uses Sketchup Pro 2021 for projects. Over the weekend, she keeps running into an issue (bug?) where, after hours of tinkering, the active file suddenly doesn’t allow her to hide objects, or unhide previously hidden objects. Right-click context menu has them grayed out for the hide or unhide respectively. This is outwardly frustrating her. The temptation is to go back to the older/working file after taking a break and starting over, but this feels impractical. I want to see if others here can help us determine if this is a known problem and/or if others run into this and have a recommended fix.

Apologies in advance if I’m not providing enough details, as I am not a user of this program. If needed, I can try to get more details with the right questions. Any help/insight appreciated!

If you can share a file with the problem, folks here will take a look.

Sure thing, is there a preferred place to upload? (50MB+)

Files smaller than about 15MB can be uploaded directly to the forum. But yours is bigger. Any file sharing site will do - Dropbox, Google drive, we transfer, etc. Just make sure the share is public and provide a link in a post here.

There was problem with a recent version go SketchUp Pro (I don’t recall if it was 2020 or 2021) where the context menu would misbehave after a while. The only solution was to restart Sketchup. A fix was provided in a later update to the version afflicted with the problem. If you are not running the last version of 2021 then you may want to install that last version (I don’t recall the exact version number or date of release, sorry).

Older file with error.skp (1.2 MB)
Older file.skp (6.5 MB)

I believe these are examples of one where the file had not yet encountered the issue, followed by one where the file stopped permitting hide/unhide.

Which one shows the problem? I’m not seeing any problem using Hide/Unhide with either one of them?

I did find other issues.

Older file with error:
Incorrect tag usage.
Screenshot - 1_23_2023 , 9_25_48 AM
And unused stuff to purge. (72% file size reduction.)
Screenshot - 1_23_2023 , 9_26_06 AM

Resulting file:
Older file with error purged.skp (338.7 KB)

Older file:
Incorrect tag usage.
Screenshot - 1_23_2023 , 9_28_18 AM

Unused stuff purged. (90% file size reduction.)
Screenshot - 1_23_2023 , 9_28_41 AM

Resulting file:
Older file purged.skp (645.1 KB)