I'm sorry, I don't can register in http://bugs.farmanager.com.
I reproduce the problem 2 times in 2 different browsers.
2. Steps to reproduce
I open http://bugs.farmanager.com> page → Signup for a new account → I insert my data in input fields →

I get e-mail → I click to link in e-mail → I get APPLICATION ERROR #1901:

3. Environment
Operating system and version:
Windows 10 Enterprise LTSB 64-bit EN
Firefox:
53.0 (64-bit)
Chrome:
56.0.2924.87 (64-bit)
Thanks.