Try using the Ladik's CascView. Warseeker's post said that one of the link will redirect you to the Zezula website, which has a download link for CascView.
I think you have already posted the link to the folliowing thread yourself, so you might use that one instead of continuing your post in this thread:
Intro: Here I will tell you how to make WC Reforged use your maps instead of the vanilla ones when you click the mission button in the menu of the game and how to keep the hero progress through multiple maps. Chapter I - Getting Ready. 1. The first step you need to do - is to enable the...
www.hiveworkshop.com
Please consider giving this mod a try:
TLDR: I've attached the fixed mission files (for the English version of the game) as a ZIP file, simply extracting the Maps folder into your WarCraft III game folder (version 1.30.4) and allowing the use of Local Files will resolve the mentioned issues. Personally for me, 1.30.4 is the best way...
www.hiveworkshop.com
Since you are using the 1.31, opening the campaign map that was modified with 1.30 might led to the corruption, so you have to do it by yourself if you're having a good IQ about JASS editing. Please do what Warseeker suggested, by using the Local Files feature and opening all of your campaign maps with the Ladik's CascView.
For the 2nd bug (missing Tichondrius' bodyguards during the Undead interlude), this can be done straightforward with World Editor:
I noticed that on certain patches the Dreardlords Convene interulude is bugged, Anetheron and Mephistroth do not appear. I found out why. Tichondrius is given the command to use "Dark Summoning" ability on them to teleport them to him. But it doesn't work since "Dark Summoning" is an item...
www.hiveworkshop.com
TFT campaign bugs in 1.31 are more serious than the ROC, especially during the Bonus Orc campaign, where you might encounter a LOT of broken strings (like all instances of Centaurs being classified as "Tauren", with one of them during Act 2 being mistakenly named "Vol'jin" or something similar). Those problems can't be fixed, iirc. That's why the following thread below explains about the list of campaign bugs on that version:
Hello, The recent updates for Warcraft 3 broke the game. Please help notify the “Blizzard classic games developers” about the bugs: Thrall’s items can be seen dropped on ground in a cutscene with Medivh near human ships in prologue. When Medivh meets Arthas on the road in the cutscene...
us.forums.blizzard.com
Also, worth noting that 1.31 is also the version where certain custom maps can cause your game to be insta-locked up after exiting the score screen. This seems to be heavily related to the triggers/JASS scripts that cause a liberal amount of memory leaks.