APPCRASH

Fix for what? Nobody can even tell what your problem is. What is "APPCRASH"? I guess you're trying to say the game is crashing? When specifically does it crash? Do you get any error messages? What are your system specs?

Problem Event Name:    APPCRASH
  Application Name:    TitanFall.exe
  Application Version:    1.0.0.0
  Application Timestamp:    530b9c18
  Fault Module Name:    materialsystem_dx11.dll
  Fault Module Version:    0.0.0.0
  Fault Module Timestamp:    530d6142
  Exception Code:    c0000005
  Exception Offset:    00000000000f1825
  OS Version:    6.1.7601.2.1.0.768.3
  Locale ID:    1033
  Additional Information 1:    9666
  Additional Information 2:    966672b34d887ab80222efb80fc89bf1
  Additional Information 3:    4137
  Additional Information 4:    4137b535862bad62c68ba27bab845ef7

ystem Information
------------------
Time of this report: 3/11/2014, 16:28:55
       Machine name: SALINEZERO-PC
   Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.130828-1532)
           Language: English (Regional Setting: English)
System Manufacturer: To be filled by O.E.M.
       System Model: To be filled by O.E.M.
               BIOS: BIOS Date: 01/11/13 15:57:45 Ver: 04.06.05
          Processor: AMD Phenom(tm) II X4 965 Processor (4 CPUs), ~3.4GHz
             Memory: 8192MB RAM
Available OS Memory: 8110MB RAM
          Page File: 2353MB used, 13863MB available
        Windows Dir: C:\Windows
    DirectX Version: DirectX 11
DX Setup Parameters: Not found
   User DPI Setting: Using System DPI
 System DPI Setting: 96 DPI (100 percent)
    DWM DPI Scaling: Disabled
     DxDiag Version: 6.01.7601.17514 64bit Unicode

What graphics card do you have? I don't see that listed.

Card name: NVIDIA GeForce GTX 660  
       Manufacturer: NVIDIA
          Chip type: GeForce GTX 660
           DAC type: Integrated RAMDAC
         Device Key: Enum\PCI\VEN_10DE&DEV_11C0&SUBSYS_26623842&REV_A1
     Display Memory: 4038 MB
   Dedicated Memory: 1989 MB
      Shared Memory: 2048 MB
       Current Mode: 1920 x 1080 (32 bit) (60Hz)
       Monitor Name: Generic PnP Monitor
      Monitor Model: ASUS VS239
         Monitor Id: ACI23D2
        Native Mode: 1920 x 1080(p) (60.000Hz)
        Output Type: DVI
        Driver Name: nvd3dumx.dll,nvwgf2umx.dll,nvwgf2umx.dll,nvd3dum,nvwgf2um,nvwgf2um
Driver File Version: 9.18.0013.3523 (English)
     Driver Version: 9.18.13.3523
        DDI Version: 11
       Driver Model: WDDM 1.1
  Driver Attributes: Final Retail
   Driver Date/Size: 3/4/2014 07:35:23, 17755424 bytes
        WHQL Logo'd: Yes
    WHQL Date Stamp: 
  Device Identifier: {D7B71E3E-5280-11CF-3156-6F061CC2C435}
          Vendor ID: 0x10DE
          Device ID: 0x11C0
          SubSys ID: 0x26623842
        Revision ID: 0x00A1
 Driver Strong Name: oem30.inf:NVIDIA_SetA_Devices.NTamd64.6.1:Section093:9.18.13.3523:pci\ven_10de&dev_11c0
     Rank Of Driver: 00E02001
        Video Accel: ModeMPEG2_A ModeMPEG2_C ModeVC1_C ModeWMV9_C 
  

You can troubleshoot your Direct X installation by trying to reinstall Direct X, or if issues persist, by contacting Microsoft support directly.