Multiple markers mean that on a particular line there is more than one error, breakpoint, TODO, etc. Even if you remove all errors, there may still be “multiple markers”. However, often a single error in the code will cause the compiler / interpreter to report multiple errors. Start with the first recorded error, find the cause and correct it. This often removes more than one error. Repeat the debugging process until all errors disappear.
I would not just delete @override. Find out why he is there. You will probably understand the error.
Good luck and happy coding!
source share