Hello,

I have migrated a site to J4 as a test. Originally, I was having problems with the site getting a 500 error that I thought had to do with an extension, but it was the template.

But as I was experimenting with installing and uninstalling extensions, I realized that Regularlabs was not installing without error, and would also error when I tried to uninstall what was there.

I have attached a couple of screenprints to you an extension in there that I tried to uninstall that generated the error. But I also get the same error when I try to install, say, Modules Anywhere.

I just realized that I can't attach graphics (or at least I can't see how), so I've generated the error again and this is what it says:

An error has occurred.
0 RegularLabsInstallerScriptHelper::preflight(): Argument #2 ($adapter) must be of type JAdapterInstance, Joomla\CMS\Installer\Adapter\LibraryAdapter given

Thanks in advance,
DAS

Hi,

Thanks for the tip. I am working on this as a test migration right now, so I'm going to start from scratch and do it again. I used a tool called Migrate4Me, but I used it on several sites and it was perfect -- never caused a problem like this.

But, like I said, I'm going to start from scratch. I'm going to go through all the J3 extensions, uninstall or update, then upgrade again, maybe using the main Joomla installer instead just to see how it behaves.

Thanks,
DAS