I tried the Improved Water Shader for Morrowind (http://oblivion.nexusmods.com/mods/23606), installing it using MPM (Morrowind Plugin Manager) then configuring the settings in MGE. However, the shader gave ugly results, so I then uninstalled it and reverted the changes in MGE.

However, now when I go outside in the game, everything is white - I can see my own hands, and text popups, but's that it. Any help appreciated.

P.

Your best bet is going to be to ditch the plugin manager and just do this manually. Download the most recent version of MGE that you are using 3.8.2 http://sourceforge.net/projects/morrgraphext/files/Beta%20Releases/MGE%203.8%2B%20SVN%20builds/mge3.8.2-rev.0178.7z/download

Or use MGE XE http://morrowind.nexusmods.com/mods/41102

Unzip the file then move it while keeping its directory structure into the Morrowind directory (as will be told in the readme) then run the distant land setup etc.

You'll overwrite any shader files or other odds and ends and have a default version of mge installed then.