"0 CALL TO A MEMBER FUNCTION SETQUERY() ON NULL" error after cloning website

I have cloned my Joomla 3.10.1 website to a new location to test some changes without working on the published version, when I try to open CF6 on administration or any page that include a CF6 element on the front end I have the "0 CALL TO A MEMBER FUNCTION SETQUERY() ON NULL" error.
Tested both cloning in a different URL and in a subdomain of the original one, all the other functions of the CSM seems to work correctly but CF6.
Any suggestion?

Hi riccardoc,
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This thread might help.
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Bob

Hi Bob,
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I did found that thread but I can't figure out the solution, can you explain me what do I have to do to correct the problems?
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Thanks so much