Post
by sozzled » Sat May 28, 2022 9:58 pm
@Webdongle: have a closer look at the screenshot. The extensions there are not "third-party" one but were developed by the J! project. For some strange reason, the update from J! 3.x to J! 4.x did not convert/replace the J! 3.x versions with J! 4.x ones and them behind.
It's possible—and I've done it—to manually unpick a J! website and remove things "left behind" (i.e. traces of extensions that are detected by J!'s discovery tool) and after doing that the discovery tool doesn't discover them (and the FPA reporting tool doesn't find them, either). It's a slow, tedious process and requires a good degree of understanding of what can be done and what should not be attempted. It's too big a process to prescribe a procedure that would cater to 50+ extensions (some of which are core ones and some of which are third-party ones) because there may be relationships between them and the core J! 4 CMS.
The tasks involved in removing, replacing and retiring "outdated" parts of J!, in order to progress to a newer version of J!, are performed by the Joomla! Update component; however, this is not always guaranteed to succeed. If the Joomla! Update facility worked every time on every website there would be no need for this forum, would there?
Migrating from J! 3.x to J! 4.x can be done in a matter of moments but it depends on what you're starting with. If, for example, you installed J! 3.10.9 and did nothing with it—added no articles or menu items, etc.—you could probably update it to J! 4.1.4 within two minutes. But if we started with a J! website that is several Gbytes in size, with 200 extensions installed, that's been developed over the course of the last ten years, say, the complexity is increased by several orders of magnitude. What may take a few minutes to migrate that J! website to J! 4.1.4 may take days, weeks or months of planning and "tidying up" before it's in a "fit state" to perform the final "update" ... and even then it may not be completely error-free.
“If you think I’m wrong then say, ‘I think you’re wrong.’ If you say ‘You’re wrong!’, how do you know?” 
