Unable to build solution

[NYP NB-IOT]

I got this error when building the solution. Rectify the problem as quickly as possible. Refer to the error circled in BLUE in the image below.

[NYP NB-IOT]

Problem Solved

[awneil]

Good news!

For the benefit of others who may come along with similar problems, please describe the solution.

And verify the answer:

[rkguy]

What was the solution 

[awneil]

LOL!

So my post asking "what was the solution?" has been marked as the solution!!

[rkguy]

Useless thread is useless