They Are Billions Message Board  

Already tried
1) building one building, then build another building and activate it during the second building.
2) training one unit, then training another unit and activate it during the training of second unit.
3) research one tech, then researching another tech and activate it during researching of second tech.

Trainer just repeats "Failed" for every attempt. Not sure whether this is map specific because I only have the 1st map unlocked.

well the last 10 update according to steam was just for store tags, so the current trainer should be working, both Caliber and Tarausplopp posted videos of it working, only thing to suggest is making sure your .NET framework is the same as listed in the instructions and more trial and error. Still an early access game and they are always temper-mental.

If you already have the latest .NET Framework installed (current is v4.7.1) and followed the steps described in this thread (which seems you have) then there is nothing else we can do about it as we cannot reproduce it.

It seems OS related. I tried using it with Windows 8.1 in my notebook and Fast Builds, Research and Training is working properly, it even has a Kaspersky Anti-Virus installed up and running.

I used it on my Desktop PC which is Windows 10 Pro, (no Anti-Viruses installed) and all options are working except those Fast Builds which keeps telling me "Failed".

That's unfortunately not true. Our trainers are written on Windows 10 x64 PCs for a couple of years now and I run the trainers on Windows 10 x64 too.

Even if you think there's no a/v installed, there's still Windows Defender working in the background...duh

... and I dusted my Windows 7 x64 installation on the very same hardware I use Windows 10 x64 on ... the trainer is working 100% and as intended.

I already did disabled everything in Windows Defender (Real-time, Cloud-delivered Protection etc all of it) and even added it on "Exclusions List"