Sometimes your computer can no longer handle .Cpp (c++) files.

Error code:
World of WarCraft: Retail Build (build 15595)
Exe: C:\Users\Nikos\Desktop\Wesi\Games\WoW\wow_434.exe
Time: Aug 14, 2015 9:45:21.640 AM
User: Nikos
Computer: NICKPC
------------------------------------------------------------------------------
This application has encountered a critical error:
The system cannot find the file specified.
Program: C:\Users\Nikos\Desktop\Wesi\Games\WoW\wow_434.exe
ProcessID: 5736
File: .\Client.cpp
Line: 3623

First solution:

• Open your World of Warcraft folder
• Delete the Cache folder in it|
• Open the Data folder
• Delete the Cache folder in it

• Open your world of Warcraft folder
• Delete the files wow.mfil and wow.pfil