Windows 8.x do not have .NET framework 2.0 installed by default.
If you don't install it as part of our install, you'll get this error when you try to use the .NET framework.
e.g.
⎕USING←'' 'System'
dtime←⎕NEW DateTime (2007 1 1)
VALUE ERROR
In the Status Window:
Could not load bridge interface library bridge141-64_unicode.dll. (Error 0x0000045a: "Unknown error")
To get this working, please start Dyalog with "Run as administrator" and go to Options→Configure→.NET Framework. Tick the box and choose v4 from the combo.
Please restart Dyalog and try again.