I get kicked out of my website's backend when I try to modify the shopper

[FX2LTD]

Hi,
I have a website with Joomla! 3.9.24 Stable [ Amani ]
I have just installed VirtueMart 3.8.8 10472

I am having this problem: when I try to work on the Shopper, as soon as I click on SAVE, I get kicked out of the backend, into the frontend. I cannot add/amend any info on the shopper.
I had this problem also before installing the latest version of Virtuemart.
The shop is currently empty, I haven't started working on it yet, as I am having issues with the basic configuration.
I have uninstalled and re-installed, the problem is not going away.

Thanks in advance

[jenkinhill]

Turn on VM debug to see if that helps. Also check your error logs.

[FX2LTD]

Thanks, I will do that

[FX2LTD]

There might be multiple issues.
PHP8 might cause some of them.
When I work on the shopper I get kicked out, when I work on simple options in the configuration, I get these messages:

get_class_methods(): Argument #1 ($object_or_class) must be an object or a valid class name, string given

Deprecated: Required parameter $htmlIn follows optional parameter $selected in /home/sites/6b/e/ee2f0fcece/public_html/plugins/vmshipment/weight_countries/weight_countries.php on line 447

Even when trying to uninstall Virtuemart, the module still stay, with the error message: 0 Undefined constant "JPATH_"

Unofrtunately I cannot switch PHP versions, if I go back to 7.4 the whole website goes down completely :-(

[FX2LTD]

Things are getting worse and worse.
I have uninstalled VirtueMart, disabled the modules that were not being uninstalled, tried to reinstall again both from the web-install inside Joomla, and the packages.
It does not reinstall
Error message attached. :-(

[Jörgen]

This looks like a PHP 8 issue. VM and some of other extensions for Joomla are simply not ready for PHP 8.

Jörgen @ Kreativ Fotografi

[FX2LTD]

Thanks,
I will have to wait for an update PHP8 compatible, unless I find a way to downgrade to PHP7.4 without losing the site completely (which is happening at the moment).
Too bad because I was going to launch an online shop with hire and booking facility, and now I will have to stop completely because of this setback :-(

Regards

[jenkinhill]

You should check your PHP7.4 server installation - it's a possibility that it is lacking some modules that Joomla needs. Maybe test with 7.3 as well? PHP 7.3.27 was released about 2 weeks ago.

There are big changes going from 7 to 8, I suspect many Joomla extensions will not be completely compatible for some time, PHP8 was only released 2 months ago.

[GJC Web Design]

Don't know why you would want to run a commercial site on a brand new php version ..

[FX2LTD]

It happened by chance...
I was having the old site on a certain hosting provider, Joomla was continuously showing messages about upgrading to a newer PHP version as the old one was going to be unsupported. I contacted the hosting with regard to the issue, their reply was that in the immediate future there was no plan to upgrade their PHP versions.
I found a new hosting, I moved onto them and (I now believe) by default their package must have been set up on PHP8, as I made no choice about it. I installed Joomla and I started working on the new site, with no technical issues. So I thought it went smoothly. I installed Virtuemart a month ago with no issue, but I left it there, as I was planning on working on the overall content of the site, before focusing on the online shop.
Until last week, when I decided to configure the basics of the shop, and I started having problems. Initially even the installation of the latest VM package went well, as I was able to choose the new beta control panel and work on the various settings of the shop.
But the issues showed once I went onto the shopper configuration. In the part, it just doesn't work.
I have wiped out and reinstalled the website's full backup taken 2 weeks ago (which was containing the initial unconfigured VM package) 4 times over the weekend, with no succes.
Then after giving up on the frustration, I tried to uninstall and reinstall from scratch, incurring in all possible problems. But it seemed that it was uninstalled in the end, apart from the modules (which I have manually disabled).
I switched PHP version to 7.4 and the whole website went down. As during the creation with the other packages I had no issues, I believe I would have to troubleshoot wat package is not happy when I donwgrade to PHP7.4, but at this point I don't know if it's worth just standing still and waiting for VM to get closer to PHP8, rather than me wasting more time trying to downgrade to PHP7.4, and then in a couple of months having a VM version that works on PHP8...
I might set up a development server and make some experiments, I don't know... for now I will just wait a bit, focus on other things, and wait to see what happens, or focus on some temporary alternatives...

Regards