The message you get is because the underlying assets don't match those that were used by the saved game. This is a feature of Civ4 when Lock Modified Assets is checked. You can't load a save from 3.13 BTS unless your BTS install is 3.13. Typically you would make a copy of the Civ4 folders before you apply 3.17 to the original. (i.e. Dual install)
Thank you for your response.
Are you saying to make a copy of ALL Civ4 folders? (There are currently seperate folders for the 3.13 and 3.17 mods in the BTS mod folder.)
In any event, how does one then use the dual installation? (A lightbulb may have gone on in my head.
I think you may be saying to install BTS to two different locations applying mod 3.13 to one location and mod 3.17 to the other; then start whichever version that one wants to use?)



