Documentation clearly states you must build twice, once in x86 and once in x64.
You can troubleshoot errors by checking its reason here.
Error code 13 (DOUBLEAGENT_STATUS_DOUBLEAGENT_VERIFIER_INSTALL_COPYFILEW_FAILED_X86) probably happened because you didn't build the solution in x86 .
i build a solution using VS 2017, but no x86 build just x64 and i ran build solution two times as stated in your README.md
even when testing DoubleAgent_x64.exe on windows 10 i got Failed (error code 13)
am i doing something wrong at a point?