Virtuemart updating troubles. From 3.0.18 ro 3.4.2

[Grigorii]

Dear support team!

We met some troubles after updating the VirtueMart

Before update we had:

- PHP 5.6.38 working in CGI mode
- Joomla 3.6.5
- VirtueMart 3.0.18
- RuposTel One Page Checkout 2.0.302.141115
- Akeeba Backup 6.1.1

The shop worked fine. Not very fast but normal.

First we have updated Joomla to 3.9.6 - good, no troubles.
After updating the VirtueMart to 3.4.2 we met the issue:

Fatal error: Call to undefined method Joomla\CMS\Component\Exception\MissingComponentException::get() in /var/www/magazini/data/www/new.magazin-integral.ru/templates/magazin-integral/error.php on line 57

Not for all products, about 10% of pages show the message.
And the pages are opening slower.

We tryied to change the PHP mode to 7.1 but got the message:
Fatal error: 'break' not in the 'loop' or 'switch' context in /var/www/magazini/data/www/new.magazin-integral.ru/components/com_onepage/overrides/vmplugin.php on line 1375

So what should we do in this case?

[Jörgen]

Looks like you have problem with Your template, magazin-integral, the overrides are giving errors.

Jörgen @ Kreativ Fotografi

[Grigorii]

Dear Jörgen.

Thank you for advice. But a have no any overrides. I mean Extensions - Languages - Overrides. The list is empty.
Any other idea?

I changed the error.php file to default (from system folder) and it shows:

404 - Component not found.
You may not be able to visit this page because of:

an out-of-date bookmark/favourite
a search engine that has an out-of-date listing for this site
a mistyped address
you have no access to this page
The requested resource was not found.
An error has occurred while processing your request.
Please try one of the following pages:

Home Page
If difficulties persist, please contact the System Administrator of this site and report the error below.

Component not found.

[jenkinhill]

Thank you for advice. But a have no any overrides. I mean Extensions - Languages - Overrides. The list is empty.

Template overrides will be in templates/[your Joomla template]/html/com_virtuemart/

Did you also update the Rupostel OPC?

[Jörgen]

Looks like you have problem with Your template, magazin-integral, the overrides are giving errors.

Jörgen @ Kreativ Fotografi

Please learn how to handle overrides in Joomla and contact Rupostel, who does this a bit differently:

Code Select Expand

/var/www/magazini/data/www/new.magazin-integral.ru/components/com_onepage/overrides/vmplugin.php

Jörgen

[Grigorii]

Thanks to all for advices. Will try to fix with OPC!