You have to do the following :-
NEW RECOMMENDED SOLUTION : Run AVA from AVA.exe which is in Binaries folder Xigncode should update normally when it finish updating close it then run it from NWZLauncher then it should work like before.
If this failed then try the solutions below.
1. Make an exception in your firewall for AVA.exe and xm.exe OR Completely close your firewall (recommended).
2. Close your Anti-virus to avoid further proplems SPECIALLY when you're using AVG or ME.
3. Close any Monitor program, any 'PC Care' programs Like Uniblue or IObit programs.
4. Open 'Task Manager' >> 'Processes' and close both processes with that name "netsession_win.exe" and close any useless process.
5. Click on Start Menu >> Search for "Run" then write 'msconfig'
it will be like that :
then Choose "Startup" tab and Un-check all the programs you don't need.
Please inform me back if the problem hasn't been fixed.