Hello,
one interesting piece of information is that it worked for weeks and suddenly stopped working. Unfortunatelly you do not tell us if it worked for weeks before upgrading and suddenly stopped after the upgrade to 2.7 or if it worked for WB 2.7 some weeks and then stopped working.
So the answer with respect to your last question is no, not specific enough. As we know that it is not easy for new users to aks the right questions, we issued guidelines for on the
help site and in the
forum rules.
Regards Christian
P.S.: Have you contacted your server hosting company and asked if they have changed server settings recently?