I sent Sir Alistair to train my cko and one of the times he just never came back. I read a solution online that involved downloading the save game editor and tweaking the save which actually worked but later the same thing happened with Leth and the fix doesnt seem to work anymore....does anyone have another solution to this problem?

This is the solution in question that i followed:
https://www.reddit.com/r/mountandblade/comments/61vqtc/companion_stuck_on_expected_back_in_approximately/