You've started a new game, right?  And unzipped the mods?  There's some help here: https://wiki.galciv.com/index.php?title=Using_Mods

You changed a value from 0 to 1, so I guess that means you edited the prefs.ini file to enable mods.  You then went into the game and enabled mods.  That wouldn't be possible if you had already enabled them when you changed the 0 to 1.  Maybe you disabled them instead.  Check again.

If that doesn't work, check your My Games directory to see if you have a GalCiv3 directory or a GC3Crusade directory or both.  If you have both, everything you do should be in the GC3Crusade directory.  Maybe you have been doing everything right but doing it in the wrong directory.

When you resynced the mods, I guess you clicked on the button labeled Resync Mods.  That has nothing to do with mods.  It is used to resync content that you subscribed to in the workshop.  I think "Resync Mods" is used because it's much shorter than "Resync Workshop Content", but it is an unfortunate choice of words.

If the problem still exists, maybe you didn't unzip the mod correctly.  In the mods folder there should be a folder that is the same name as the mod.  Opening that folder should show one or more folders.  The possible names of these folder are core, game, text and possibly other names.  If you don't have this structure, something was done wrong.

If nothing has worked, please list the mods and where you got them.  I'm still wondering if you mean mods or something from the workshop.

Ok - found the GC III Crusades file - now confused as to which one my Icon opens up when I click on it but prefs file is the same as msg before and back to square one

I'm now convinced you have extracted the mods correctly and have them in a mods folder.  I'm not sure I understand which mod folder.

I get the impression you have two folders for the game in your My Games directory, one named GalCiv3 and the other GC3Crusade.

Since you are trying to use mods for the Crusade expansion, I have to assume you have that expansion and maybe more.

Which version of the game do you have?  The main title/menu screen will tell you.

If you do have Crusade or Intrigue or Retribution or more than one of them, you need to be using the Mods directory in Documents\My Games\GC3Crusade for all your mods.  The game will ignore the GalCiv3 directory if the GC3Crusade directory exists.

It's possible that some of the mods you want to use won't work correctly with the version of the game you have and cause strange results during a game, so keep that in mind.

Until we get mods working, you should ignore the prefs.ini file.  Use the Options menu in the game to turn mods on or off.  The ResetPprefs=0 is correct and shouldn't be changed.

Finally, I don't think 77 is all that old.  I'm 72, and most of the time I don't think I'm old.  

Last night about 2 I realized how dumb my emails must sound.  I know the prefs.ini is the whole list of codes - duh.  So here is the gist - I have two GC3 folders - on just plain GC3 that all the mods and current game saves to and one GC3 Crusade that does not show any game past 2017.  When I click on the game icon to start a new game i am assuming it uses the GC3 file to open as I have no specific start game icon for Crusade.  I have the exact same mod folder in both and the same mods enabled in prefs.ini. Appreciate all you have done to educate me but may have exhausted your good nature.

If you still haven't tried placing your mods in the Crusade folder, try doing so.  Just because you don't think it is being accessed, that is indeed the folder being accessed.

To all - did exactly as you said and all are in the correct  GC3 Crusades Mods folder - will try a new game tomorrow and see what happens.  Will advise.  Many thanks.  Jim 

Tried a new game 7 times - it crashes each time - interesting that I can play a saved game.  Guess I will have to uninstall and start over- wow this has been a real interesting exercise.

In addition to what the Admiral said, please list the mods you are using. Some mods (and I'm thinking now about mods that include custom ship parts) have caused problems.