System.DllNotFoundException: Unable to load DLL 'TIDAS.DLL' (Exception from HRESULT: 0x8007007E)

I get the error:

System.DllNotFoundException: 'Unable to load DLL 'TIDAS.DLL':
The specified module could not be found. (Exception from HRESULT: 0x8007007E)'

I keep getting that runtime error.
But I have all the files that goes with that .DLL.

I have a solution that someone else made and it works fine.
But my solution... I keep getting this error and I do not know why...

I am writing this program in C#.
I have all the same .DLLs like in the other solution...

Any idea ?