Warning: trim() expects parameter 1 to be string

-- url of the page with the problem -- : scarvesaustralia.com.au
-- HikaShop version -- : 2.6.1
-- Joomla version -- : 3.5.1
-- PHP version -- : 5.6
-- Browser(s) name and version -- : Safari 9.0.3
-- Error-message(debug-mod must be tuned on) -- : Warning: trim() expects parameter 1 to be string, array given in xxx/scarvesaustralia.com.au/libraries/vendor/joomla/registry/src/Format/Json.php on line 50

We are encountering the error message:

Warning: trim() expects parameter 1 to be string, array given in xxx/scarvesaustralia.com.au/libraries/vendor/joomla/registry/src/Format/Json.php on line 50

We have renamed the template's custom html and found that this error message is only triggered when Hikahop is run.

Do you know about this and would you have a solution?

Thank you

We have updated Hikashop to 2.6.2 and initially it seemed to be resolved. However we just discovered a new incidence and still we do not have a further clue what it could trigger.

Done. Thank you.