You have to update docker plugin to latest once you upgraded to Easysocial 3.

https://stackideas.com/apps/item/3336-docker

If the issue still persists, can you update your site backend and FTP access at http://stackideas.com/dashboard/site so we can better have a check?

well, I've installed the docker 2.1.6 same error. BUT, when I disable the docker the site works without error. please advice ( the test site where I try to figured it out about this error is offline on my computer )

Thank you in advance for your help debuging this issue ...

Try this following method and see how it goes.

1. Try switch to Joomla default Protostar template
2. Enable debug mode setting from backend > system > global configuration > system > Debug System
3. And Enabled Error reporting to maximum

And see which file hit this error.

ok I will test as you advice, but please tell me when you'll have a Docker plugin app compatible with ES 3.0 ... on the page of the Docker plugin it show 2.1.6 and no compatibility with the ES 3.0 ... please advice

Hm, the current docker plugin 2.1.6 already compatible with Easysocial 3, so I suspect other plugin caused this issue on your site.

Can you try follow my method and see whether possible to show the full error message on the site?

Or you can try rename one by one plugin folder from your JoomlaFolder/plugins/system/...

By the way, keep us update then.

I solved the issue with docker runing the fix from System - Global Check-in ... but I found other issue : when the esysocial are locked and someone try to access an easysocial link I've got a notice message : Joomla\CMS\Filesystem\Folder::create: Path not in open_basedir paths

Please advice

Thanks for getting back to us you solved that initially issue.

Joomla\CMS\Filesystem\Folder::create: Path not in open_basedir paths

Regarding this error, we never encounter this issue before so that is difficult for us to know where went wrong.

I would strongly suggest you that temporary push your local site to live so we can able to check this directly on your site.