we updated Magento from 2.2.3 to 2.2.6. then the error started, we changed the PHP to 7 from 7.1 but we still have the same issue.
my frustration is that the hosting company for 2 weeks not sure about the issue.
is it wise to keep Magento 2.2.6 or downgrade?
is it safe to work on the development site while we trying to solve the issue?
is it wise to download the site on a local server and work on it then upload to the live site when issue resolved?