WebPlus X6: Pictures are gone

hello everyone

when i open my page with my webplus program, and click the galleries, it doesent show the thumbnails in the folder.also they dont show up, when i preview the site. i have to reupload them.
they are still visible online in my already uploaded version though, just not in the version kept on my pc.
this is strange, since i did not move the pics to new folders or places in my laptop...what i did do is open the page with WP and try things, and watch it with the preview, however, those changes where never saved...

ps. when i open webplus i get a message: could not find resource file, choose new file or folder? i alwys pchoose "no to all".

thanks for your help, and greetings

robozo