Why do compiler gives error instead of warning for variable which is assigned but its value is never used

Question

I know there are lot of question which is asked previously about

The variable which is assigned but its value is never used

Here,Here and Here

I am getting compile time Error instead of warning which causes compile or rebuild to fail. i didn't update my Visual studio 2015 nor do i installed any VS extension

so my question is what can i do so Visual studio show warning instead of Compile time Error.

Answer 1

In the project-properties is a setting "Treat warnings as errors" which you apparently switched on.

To undo: Project->Properties->Build->Treat warnings as errors->None
(None is the default-setting for new projects.)

Read this for reference.

Note:
It's certainly still a good idea to set this setting to All, to ensure the code is error- and "garbage"-free.