Dashboard changed to plugin example

Hey everyone

I’ve been making a form for the website http://www.clearlyglassltd.co.uk/ and installed ‘ms-dropdown’ (https://github.com/marghoobsuleman/ms-Dropdown) which would allow to have thumbnails in drop down menus however after putting the files in via ftp visiting the dashboard takes me to an example form that ms-dropdown created as seen with the link below.

http://www.clearlyglassltd.co.uk/wp-admin/

I’ve removed all the files I added and the example page is still here but without the ms-dropdown functionality. Will I be able to restore the dashboard without reverting any work I’ve throughout the site recently?

Thank you!