Error message in Categories

[Tryer]

Having upgraded my Joomla 3 site to Joomla 4, I now see the error message below when opening the category general information in the Admin panel:
Details
Notice: Undefined property: VirtuemartViewCategory::$parent in /home/sites/mysite/public_html/j4/administrator/components/com_virtuemart/views/category/tmpl/edit_categoryform.php on line 54 Notice: Trying to get property 'virtuemart_category_id' of non-object in /home/sites/mysite/public_html/j4/administrator/components/com_virtuemart/views/category/tmpl/edit_categoryform.php on line 54 m

Please note that the Joomla 4 site is currently in a subdirectory "J4" on the live J3 site.

However, the categories apparently function normally.

Can anyone please advise on what might be the problem?
Comments appreciated.

Joomla 4.0.22
PHP 7.4.33
VM 4.3.3

[Tryer]

Does it help that this is the bit of code that seems to be the source of the error?

<?php echo VmHTML::row('raw','COM_VIRTUEMART_CATEGORY_NAME',VmHtml::input('category_name',$this->category->category_name,'class="required inputbox"').$this->origLang); ?>

[GJC Web Design]

have u tried VM4.2.0?  Might be fixed..

https://virtuemart.net/downloads

[Tryer]

Thanks for the tip - I'll try it asap.

[Tryer]

OK, I upgraded to VM 4.2 but the error remains the same.