There is a problem with the modem

[Wilczek228]

I did everything right, all files are in place and a message appears
please help

[totalsource]

I just solved this problem for myself. When downloading the old game version, I used DepotDownloader instead of using the Steam Console. For some reason the Console grabbed the wrong game version. Using DepotDownloader to grab the old manifest instead of using the Steam Console does the trick. I followed Verulean's guide on how to get it done, linked here: youtube.com/watch?v=44HBxzC_RTg
When you get to the cmd command, copy/paste the following string to download v1.56 of TLD:
dotnet DepotDownloader.dll -app 305620 -depot 305621 -manifest 8350414681168775351 -username -password

Game version is now v1.56 and ModLoader should work fine.