I had the same issue and looking at the batch file I found that the line to start FSUIPC was commented out, don't know how this could happen. Removing the : from that line it worked again. You might also want to check if the path is correct and you can reduce that delay set in the file to start FSUIPC after MSFS has launched.
:: Variable to hold delay (in seconds) after MSFS has been started and before FSUIPC7 is started
set /a delay = 15
set "splash=%temp%\tmp.hta"
:: all lines beginning with min. 6 spaces are redirected into the HTA file
>"%splash%" (type "%~f0"|findstr /bc:" ")
:: cmd.exe /C start mshta "%splash%"
start mshta "%splash%"
:: wait for MSFS to start (2mins)
::timeout /t %delay% /nobreak > NUL
:: start FSUIPC7
start "" "D:\Program Files\FSUIPC\FSUIPC7.exe"