Error: Unable to access jarfile jetty/start.jar

Hello

i try to install X wiki Entreprises

i did all the steps from this tuto imagehttps://youtu.be/QP_N5U_GIJY

And when i want to open the file “start_xwiki.bat” i have this message :
Error: Unable to access jarfile jetty/start.jar

What i am supposed to do ?