This is not an actual question, instead it's a warning to whose uses MS 126.96.36.199.
A couple weeks ago we updated our .NET from 4.5 to 4.7 and only yesterday we noticed that one of the sections of our website that runs a huge package (a TON of variables and almost 3K lines of code) had stopped to work.
Initially I thought that there was something broken in my code (although there wasn't a reason for that because it was working fine before) and so I revised it carefully. It took me hours chasing my own tail until to conclude that there was nothing wrong.
Then I just proceeded and started to remove chunks of code to see in what point the package would get back to life again. When it finally worked I ended figuring that the problem was not the code but the AMOUNT of code. Yup! When I finally managed to remove code enough to reduce the package size to something around 600 lines it worked. When I got this point the simple addition of PLAIN TEXT was sufficient to crash the page again!
Since the cause of the problem was the size of the package it was not too hard to figure that it was provoking a stack overflow in the SF core. Possible reasons: a corrupted core or bad memory in the server. But then suddenly I remembered that we had updated .NET from 4.5 to 4.7 in the very same day where the problems started to happen. Long story short we downgraded back to .NET 4.5 and guess what? Everything came back to normal behavior instantly.
So, if you use MS 188.8.131.52 and after to update to .NET 4.7 begin to experience issues, try to roll back to 4.5.
PS: The problem won't show up in every package. We have over 150 XML packages in our website and it happened only in our biggest and more complex one.