IPhone doesn't recodgnize remembered Wi-Fi?

My iPhone 5C doesn't recodgnize a remembered Wi-Fi. If i try to go to "Other…" and enter the information it says that it can't connect.

Because it is unhealthy turn Wi-Fi off.

You need to *forget this Wi-Fi* - and then re-connect as if it were a new one. Digital stuff does all kinds of strange things. Microsoft used to say that their software had NO BUGS - it just "occasionally developed random features."