Zend certified PHP/Magento developer

Can’t create configurable product due to error ‘Class catalog/product_attribute_backend_recurring does not exist’

On creating a configurable product there’s just the returned message of ‘There has been an error processing your request’ & ‘Class catalog/product_attribute_backend_recurring does not exist’

To begin with, I was seeing ‘catalog/product_attribute_backend_groupprice’ and then ‘catalog/product_attribute_backend_msrp’ but I fixed those in turn with changes to the eav_attribute table & the backend_model with ‘MagentoCatalogModelProductAttributeBackendGroupPrice’ and ‘MagentoCatalogModelProductAttributeBackendPrice’

Nothing seems to work with recurring though as it’s not related to an item. I’ve checked the eav_attribute table in two other Magento installations one with the same version of 2.3.5-p1 and the other 2.36 and neither have a recurring_profile entry. So I assume it’s caused by an extension but can’t figure out which one.

debug.log
[2022-02-22 20:02:32] main.CRITICAL: Class catalog/product_attribute_backend_recurring does not exist [] []
[2022-02-22 20:02:39] main.ERROR: Class catalog/product_attribute_backend_recurring does not exist [] []
[2022-02-22 20:02:39] main.CRITICAL: Class catalog/product_attribute_backend_recurring does not exist {“report_id”:”4450e0e19a47108077310330448a740e75fa27a40a376e9eaac04f06ac916aa5″,”exception”:”[object] (ReflectionException(code: -1): Class catalog/product_attribute_backend_recurring does not exist at /***/public_html/tsf/vendor/magento/framework/Code/Reader/ClassReader.php:26)”} []

I’m also getting these 2 issues but believe they are separate…

[2022-02-22 20:02:23] main.DEBUG: cache_invalidate: {“method”:”GET”,”url”:”https://www.stitchfactory.co.uk/magento_backend/admin/dashboard/index/key/e1506c536e6f65529a3f0f5514*******************************/”,”invalidateInfo”:{“identifier”:”LOCKED_RECORD_INFO_BLOCK_9810e2a6c8c8b1a8e981e6c03e28c1c5462a2877″}} []

[2022-02-22 20:02:25] main.CRITICAL: Warning: DOMDocument::loadXML(): Empty string supplied as input in /******/public_html/tsf/vendor/magento/framework/View/Element/UiComponent/Config/DomMerger.php on line 327 [] []

Magento ver. 2.3.5-p1

Where should I be looking?

I’m still a bit of a novice when it comes to debugging Magento although I’m learning fast.