I've tried to install a several mods and they all mess up, causing problems.
I use Nexus Mod Manager to install the mods from Planet Elder Scrolls. When I'm installing the mod, a dialog appeared, saying some files were already there and asked me if I want to overwrite them. I clicked "Yes to all" and it didn't complain after that.
However, when I launched the game, another dialog appeared saying "master file TR_XXX.esm is missing" and it gave me "Yes" or "No" choice to continue, but both choices lead to the game crashing.
I'm able to re-launch the game only if I uninstall all the mods I've installed using the Nexus Mod Manager, leaving only the mods installed outside of it (such as Better Bodies and Morrowind Overhaul). Nevertheless, I still get a dialog that says:
The currently selected master file and plugins do not match the ones used by this saved game. Errors may occur during loading or game play. Do you wish to continue?
How can I properly install mods in Morrowind so I don't receive errors, crashes, and warnings like these?