Not to say that Creative Suite has turned into an overbloated collection of uneeded, unused and insane updates but OH 
MY GAWD the newest InDesign update was an absolute horror show. Usually I just let things slide because I’ve been using the programs for years and can find what I need when I need it but I reiterate. OH MY GAWD Seriously, “copy” and “paste” weren’t available. And that was just the freaking tip of the iceberg. I finally had to uninstall it and roll it back two versions to actually work. Anyone else or was it just me?
It’s typical in an update. I never update straightaway and have auto update turned off unless there’s a feature i really need.
And i always keep previously installed copies of the software i have all the way back to 2021.
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Usually resetting preferences fixes things.
And creative cloud cleaner tool is pretty useful.
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Updates can cause unexpected things like menu items not working and it’s usually a preference reset that fixes it.
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There are other factors at play like mac os permissions, hence why some things don’t work cos Adobe can’t write to the parts it needs to.
I’ve never had any software update behave this badly, and I didn’t update it, did it automatically. If I had my druthers I’d still be using CS6. Why do you keep installed copies? The earlier versions are available in Creative Cloud, you uninstall the version you have and then reinstall an older version. I just make sure I have .idml files so I can open them.
Did resetting InDesign preferences fix it?
Does it happen in a new document as well as existing files?
You can generally only install the current major version and the previous major version through Creative Cloud now, so I never uninstall older versions unless I absolutely have to. Adobe even removes the previous version by default during an update unless you tell it not to.
That’s why I’ve still got versions going back several years. I don’t necessarily use them regularly, but if I need to open or troubleshoot something in roughly the environment it was created in, I can. Otherwise I’ll move it forward to whichever version I regard as my most stable working version usually the release before the current one.
As for your update, I’m not suggesting Adobe gets a free pass. If an update leaves basic things like Copy and Paste apparently unavailable, something has obviously gone badly wrong. But that doesn’t necessarily mean the actual InDesign release itself is fundamentally broken.
An Adobe update is also migrating preferences, workspaces, plug-ins/settings and interacting with OS permissions and existing application files. Any one of those can go wrong during an update. Corrupt or incompatible preferences in particular can produce some very bizarre behaviour, which is why resetting preferences is usually one of my first troubleshooting steps.
So yes, it was an Adobe update that triggered it, but I wouldn’t automatically conclude that “the new version is unusable” from one installation. Sometimes the update itself is fine and the installation/migration is what went sideways.
And this is exactly why I turn automatic updates off. On a machine I rely on for work, I want to decide when a major application gets changed, not discover one morning that Creative Cloud decided for me.
You can turn off auto updating in Creative Cloud preferences.
And you can keep your previous installs too.
Funny enough, I was working on 2023 up to this year. I wanted to go to 2024, but I must have missed installing this version so I moved to 2025 - so in fact I am missing 2024 - no big deal.
I never remove them.
It would also help to know what environment you’re running it in. What OS and exact version are you on? Are you using a VPN, corporate network, antivirus/security software, firewall, endpoint protection, cloud-sync software, font managers, third-party InDesign plug-ins, or anything else that could interfere with files being written or permissions being changed during an update?
Those things matter. An InDesign update isn’t happening in isolation it has to replace application files, migrate preferences and workspaces, access user folders, fonts, caches and various system locations. VPN/security software, restricted permissions, third-party plug-ins, damaged preferences or even remnants of an older installation can interfere with that.
Copy and Paste disappearing is certainly not normal behaviour for the release, so something has gone wrong. The useful question is whether it’s actually a bug in that version of InDesign or whether something went wrong during the update/install/migration process.
Nope, nothing different for the last 5 years since we moved to the cloud version. Same machine, same account, same internet, same office, same desk chair. Trust me it’s not me, it’s them. And I was really just venting. Rolling it back to a previous version fixed it.
I still use my CS6 Suite! 
No need to upgrade given my workflow and (admittedly weird) client needs.
Still haven’t answered whether you tried resetting the preferences, which was really the main thing I was asking.
Since rolling back fixed it, that’s fine for now. But it would have been useful to know, because without the OS version, exact InDesign version, whether preferences were reset, and the other environment details, there isn’t really enough information to troubleshoot what happened.
And “nothing has changed in five years” doesn’t necessarily mean the environment hasn’t changed. The OS changes underneath you. Apple and Microsoft change permissions, security policies, Full Disk Access, application access to folders, background processes, security requirements, etc. Creative Cloud changes too. None of that requires you to consciously change anything yourself.
So it absolutely could be an Adobe problem, but we don’t actually have enough information to establish that. All we know at the moment is that the newer version misbehaved on your system and rolling back resolved it.
That’s why I was asking the questions rather than simply saying “Adobe broke it.”