Load balancing: unable to update/edit (There was an error when executing operations.)

[fborges]

This is my first time writing in this forum, so I apologize in advance for any mistakes or lack of crucial pieces of information.

We're using a Classic HTTP(S) Load Balancer to redirect users from some URLs to backend services. It has 13 backend services defined on it and plenty of Host and Path Rules, many of which have multiple hosts defined on it. It also has one Frontend IP Address and Port defined (which is 443) with a valid certificate.

From the point of view of the resources that are using it, it's working as expected; the problem is that we're unable, when editing it, to update its configurations, even when nothing is changed (the following error is thrown in the notifications: "There was an error when executing operations"). We tried to find logs regarding it, but we were unable to do so. 

Since it was working just fine the last time an entry was inserted (and now the mere attempt to click on the update button without changing anything is enough to throw the aforementioned error), we're suspecting that, whatever the problem is, it may have to do with an external thing that could have been done (such as a backend service or an URL Rule has been deleted).

We also checked that the other load balancers that we have (or even new ones that we create) don't have that problem.

I'd also like to mention that I'm not the only team member that configure the environment, so some thing may have been changed without my knowledge.

To sum up, how can we proceed with such a generic error ("There was an error when executing operations") when trying to edit our Classic HTTP(S) Load Balancer?