I wouldn’t blame them for it, not because they are one of our recommended hosts https://www.ads-software.com/hosting/ , but because it’s not an obvious problem offhand. I’m sure we all would have found the cause eventually.
In order for us to have noticed it, we would have needed the results from your browser’s JavaScript console, which is why I asked yesterday: https://www.ads-software.com/support/topic/appearance-on-admin-page-no-functionality?replies=36&view=all#post-8669213
Based on what your friend quoted, I assume that this is what your friend did.
To give a more “physical world” anecdote, these kind of things remind me of why my truck’s engine needed to be rebuilt. I was accelerating to freeway speeds, and suddenly it started violently shake. We went through 2 mechanics at the dealer before the 3rd decided to disassemble the entire engine and found that a spring roughly the size of a mechanical pencil’s spring had broken, causing a valve to fail.
I didn’t blame the other 2 mechanics for missing it, the truck had to make its way to someone who had the tenacity to disassemble the entire engine and inspect every single part until winding up with a broken spring that was about an inch long and 2 millimeters wide.
All web software is kind of like that engine. Millions of problems can be caused millions of ways, and finding the problem is often just the luck of running the right test or looking directly at the right competent.