DLL worked on WPF but not on Unity.

I have a DLL file (not my custom dll) work as communicator to another devices. There is an example solution (WPF) that use the file which working fine. I tried to create another project (WPF) to test again the file and it is also good. But when I import on Unity (2019.2.0f) to use, it keeps crashing everytime I play.
Is there any reason makes it crashing? Or is there anything I should look into first before using the file?
Please help, thanks in advance.