site locked (all locked, blank pages) after vm update

[bladerunner]

joomla site vrs 2.5
updated virtuemart..... all went white.
via config.php moved debug info to maximum.
this is what appears now in the site, either back and front:

Fatal error: Uncaught Error: Call to undefined method JSite::isClient() in /web/htdocs/www.mysite.it/home/plugins/system/vmLoaderPluginUpdate/vmLoaderPluginUpdate.php:50 Stack trace: #0 /web/htdocs/www.mysite.it/home/libraries/joomla/event/event.php(71): plgSystemVmLoaderPluginUpdate->onAfterRoute() #1 /web/htdocs/www.mysite.it/home/libraries/joomla/event/dispatcher.php(161): JEvent->update(Array) #2 /web/htdocs/www.mysite.it/home/libraries/joomla/application/application.php(642): JDispatcher->trigger('onafterroute', Array) #3 /web/htdocs/www.mysite.it/home/libraries/joomla/application/application.php(257): JApplication->triggerEvent('onAfterRoute') #4 /web/htdocs/www.mysite.it/home/includes/application.php(132): JApplication->route() #5 /web/htdocs/www.mysite.it/home/index.php(36): JSite->route() #6 {main} thrown in /web/htdocs/www.mysite.it/home/plugins/system/vmLoaderPluginUpdate/vmLoaderPluginUpdate.php on line 50

how to solve with no loss all site ?

[bladerunner]

sounds like the /libraries has been changed and system does not found necessary functions.

test done: get the /libraries from daily backup, swapped, and error now is different:

Unable to load session storage class: database

this is a clue that the troubls deals with /libraries

[jenkinhill]

You updated to VM3.2.6 on a live site instead of following the standard procedure of testing on a backup of the site first? Since version 3.2.4 VirtueMart is no longer compatible with Joomla 2.5.x - see the compatibilities on http://dev.virtuemart.net/projects/virtuemart/files

Since the Joomla people declared that all versions before J3.7.1 were insecure and should not be used on live sites there has been no testing of VM on old Joomla versions. Now they tell us that all versions before J3.8.2 are insecure...

You should revert to your latest pre-update backup and give serious consideration to migrating to Joomla 3.8.2

[bladerunner]

ehhh I know. hitted "update" before thinking at...
migration to 3.8 is on paper ....
VM should do a check b4 to update and say "Joomla version dont allow update"

[Milbo]

I am sorry. It happened faster than intended that it breaks old j2.5 installation. But it cant be too much. JSite::isClient() can be replaced.

[GJC Web Design]

In the interim try unpublishing the new vmLoaderPluginUpdate system plugin.. either rename the folder or disable in the #__extensions table

[bladerunner]

rien a faire.
get old backup and restored.
back to work.
this version is definitely NOT good for j2.5. We  hope to have a check by component itself before installation-