Manually removing add-on if site won't load

I'm setting up an intranet using Plone 5.1.6 and one of our requirements is multi-language support. I've just enabled the two Multi-Language add-ons that were available in the default Add-On set. The first went fine, but after enabling Multi-Language Archetypes, I can no longer access the site at all. This appears to be a known issue, discussed here:

Multilingual issue

I've brought up the ZMI and gone to portal_quickinstaller, selected it there, and clicked "Uninstall", and I receive the following error:

ValueError('Empty module name',) (Also, the following error occurred while attempting to render the standard error message, please see the event log for full details: 'RequestContainer' object has no attribute 'portal_factory')

(This is the same error that comes up if I try to browse to any page of the Plone site itself.)

I do have shell access to the server, if there's a way to manually remove it there.

Alternately, is there an easy way to "reset" the site without killing the whole software install? We had a tricky time getting this far, but the actual site hasn't been customized at all yet other than configuring a couple of add-ons, which I could re-do. (i.e. we haven't yet generated any content.)

Since a full site reset was an option for me, I wound up just going into the ZMI, renaming the existing site, and then creating a new site with the desired site name. However, I'll leave this topic up in case anyone else runs into the same issue and doesn't have that option.

The easy way to undo things is to go into the ZMI -> the site -> Undo tab. Check the box next to the database transaction you want to undo then press the Undo button. It can be hit or miss if it works, but when it works it’s a blessing.

You don’t say what error messages appear when you try to access the site after enabling that 2nd add-on, either on screen or in the instance.log

This is 'a bit guessing', so please correct me if I am wrong:

portal_factory is an 'Archetype thing', so to uninstall the multilingual add on you probably need Archetype installed.

So, if everything else fails, you could try to install archetype (content types) support, uninstall 'Multilingual', and then uninstall archetype (content types).

Again: guessing, but it is probably worth a try

After enabling the second add-in, the add-ins site page is immediately replaced with the error that I mentioned above:

ValueError('Empty module name',) (Also, the following error occurred while attempting to render the standard error message, please see the event log for full details: 'RequestContainer' object has no attribute 'portal_factory')

No other errors are produced on screen. Unfortunately, since I've since deleted and re-created the site, I don't have access to the instance.log any longer.

However, if someone needs the logs from when that happens, it should be easy to reproduce -- install Plone 5.1.6, enable add-on. If it would be extremely helpful, I can try to set up a spare VM or something and do this. (I'm loathe to do it on the site I'm actively working on, for obvious reasons.)

Thanks! I don't actually think I need the second add-in that was causing the failure. It was just listed as a multi-language add-in, and I was looking for multi-language support, so I installed it. But the first multi-language add-in seems to do the trick. (I still need to wrap my head around how it works, but it did add multi-language support by enabling just that one.) You may be right in that the second add-in may only be there for people who have archetype content types installed.

For Plone 5, you want to use Anything related to Archetypes is not really supported anymore and is not available in Plone 5.2 running on Python 3

Yeah, is, I believe, the Add-On I was referring to as "the first one" -- it appears in the Add-Ons page as "Multilingual Support".

I think (another guess) that the wrong profile was installed, since there is one for Dexterity and one for Archetype.

If this is a Plone UI problem you could go to the ZMI /portal_setup and import the dexterity profile