Error with M2Web & TightVNC

We have install TightVNC portable 1.3.10 on a windows computer
IP adress & port (5900) are configured

By connecting with ecatcher and starting vncviewer it’s work perfectly

By using M2Web + configuration in ecatcher like the attached file, it’s not working ? we have next error: An internal error occurs
Config%20Ecatcher

Any suggestion?

Have you tried clicking on the advanced options and changing the color depth?

Also, I believe you will need to set a password in order for it to work.