After updating to vs2017.3, the breakpoints will not be hit

Try to clear/delete all breakpoints from the Debug menu, choose Delete All Breakpoints.

Note: The reason is that it refreshes your Visual Studio setting file of your project.

I lost 30 minutes reading and trying solutions. My case was completely different and the solution was very easy. I just had to change the project to Debug. I do not know how the value changed to Release. With VS2017, right click on the solusion then / properties / Configuration properties / Configuration, change the projects to Debug.