I have the impression that a disproportional large fraction of overleaf users don't notice error messages, a typical comment stream often goes like:
Question: Why is the image placed incorrectly?
me: Can you add a MWE
OP: sure, here is the overleaf link: ...
me: Your example code does not compile and results in error messages about
Undefined control sequence. You need to define
OP: My code does not have errors. Look at the overleaf link, it compiles fine
me: Just because overleaf is exceptionally good at hiding error messages, does not mean that there are no error messages ...
The above dialogue is fictional, but many of you have probably experienced similar situations.
I think there might be some possibilities to tweak their UI to make users more aware of error messages (maybe some dialogue message "there are errors - go back to editor to fix or ignore and show pdf", just a quick idea off the top of my head).
Now it probably won't make much impression on overleaf if a none customer like me writes them "I have the impression your users are unaware of errors", but if there would be a list of questions which demonstrates this problem, maybe the impact would be higher. Unfortunately it is hard to search for this on the main site, because this problem is often discussed in comments and the questions are (correctly) not tagged with overleaf, because the tex problem is unrelated to the platform used.
Please help me to compile a list of questions, which were caused or made more complicate to solve because the OP did not notice error messages on overleaf
(my plan would be to collect examples over the next month or so and depending a bit on how many are found until then, write to overleaf)
I know that also many users of editors like texstudio ignore error messages, but I have the impression that most of them are aware that there are some red messages highlighted at the bottom left, they just argue that "the pdf looks fine" and ignore them anyway, which is equally bad, but another problem.