I had that same issue while i was trying to add a new .lib , .h and .dll files
I'm not an expert , I'm just a student, here's how i solved it after hours of trying :
when you place your library file , pick either x64 or x86 , DON'T DO BOTH
then before running your code there's a category beside the debugging green arow it's called solution platform
( it says x64 for me) match it with the library file you chose . and run your code .
it worked for me at x86, I'll try to understand the science behind it one day lol, i hope it works for you as well ;)