Try running as an administrator?
Alternatively, copy and paste
[Engine]
CustomRenderingSettings=1
PerformancePlatform=2
[Gameplay]
ShowCombatLog=0
ShowSubtitles=0
[Graphics]
Brightness=1.17949
[Input]
DoubleTap=0.3
KeyboardLayout=QWERTY
[InputQWERTY]
IK_0=(Gamekey=GI_Holster,Value=1.000000)
IK_1=(Gamekey=GI_Steel,Value=1.000000)
IK_2=(Gamekey=GI_Silver,Value=1.000000)
IK_3=(Gamekey=GI_Hotkey03,Value=1.000000)
IK_4=(Gamekey=GI_Hotkey04,Value=1.000000)
IK_5=(Gamekey=GI_Hotkey05,Value=1.000000)
IK_6=(Gamekey=GI_Hotkey06,Value=1.000000)
IK_7=(Gamekey=GI_Hotkey07,Value=1.000000)
IK_8=(Gamekey=GI_Hotkey08,Value=1.000000)
IK_9=(Gamekey=GI_Hotkey09,Value=1.000000)
IK_A=(Gamekey=GI_AxisLeftX,Value=-1.000000)
IK_C=(GameKey="GI_Character",Value=1)
IK_CapsLock=(Gamekey=GI_WalkFlag,Value=1.000000)
IK_D=(Gamekey=GI_AxisLeftX,Value=1.000000)
IK_Delete=(GameKey="GI_Cancel",Value=1)
IK_Down=(GameKey="GI_Down",Value=1)
IK_E=(Gamekey=GI_LockTarget,Value=1.000000)
IK_Escape=(GameKey="GI_Exit",Value=1)
IK_F=(Gamekey=GI_CircleOfPower,Value=1.000000)
IK_F5=(GameKey="GI_F5",Value=1)
IK_I=(GameKey="GI_Inventory",Value=1)
IK_J=(GameKey="GI_Journal",Value=1)
IK_LControl=(Gamekey=GI_FastMenu,Value=1.000000)
IK_LShift=(Gamekey=GI_WalkSwitch,Value=1.000000)
IK_LeftMouse=(Gamekey=GI_AttackFast,Value=1.000000)
IK_M=(GameKey="GI_Nav",Value=1)
IK_MiddleMouse=(Gamekey=GI_Block,Value=1.000000)
IK_MouseX=(GameKey="GI_MouseX",Value=1)
IK_MouseY=(GameKey="GI_MouseY",Value=1)
IK_Pad_A_CROSS=(Gamekey=GI_Accept_Evade,Value=1.000000)
IK_Pad_B_CIRCLE=(Gamekey=GI_UseAbility,Value=1.000000)
IK_Pad_Back_Select=(GameKey="GI_Exit",Value=1)
IK_Pad_DigitDown=(Gamekey=GI_Holster,Value=1.000000)
IK_Pad_DigitLeft=(Gamekey=GI_Steel,Value=1.000000)
IK_Pad_DigitRight=(Gamekey=GI_Silver,Value=1.000000)
IK_Pad_DigitUp=(Gamekey=GI_Adrenaline,Value=1.000000)
IK_Pad_LeftAxisX=(Gamekey=GI_AxisLeftX,Value=1.000000)
IK_Pad_LeftAxisX=(Gamekey=GI_AxisLeftX,Value=1.000000)
IK_Pad_LeftAxisY=(Gamekey=GI_AxisLeftY,Value=1.000000)
IK_Pad_LeftAxisY=(Gamekey=GI_AxisLeftY,Value=1.000000)
IK_Pad_LeftShoulder=(Gamekey=GI_LockTarget,Value=1.000000)
IK_Pad_LeftThumb=(Gamekey=GI_Medallion,Value=1.000000)
IK_Pad_LeftTrigger=(Gamekey=GI_FastMenu,Value=1.000000)
IK_Pad_RightAxisX=(GameKey="GI_AxisRightX",Value=1)
IK_Pad_RightAxisY=(GameKey="GI_AxisRightY",Value=1)
IK_Pad_RightShoulder=(Gamekey=GI_UseItem,Value=1.000000)
IK_Pad_RightThumb=(Gamekey=GI_CircleOfPower,Value=1.000000)
IK_Pad_RightTrigger=(Gamekey=GI_Block,Value=1.000000)
IK_Pad_Start=(GameKey="GI_PanelSelector",Value=1)
IK_Pad_X_SQUARE=(Gamekey=GI_AttackFast,Value=1.000000)
IK_Pad_Y_TRIANGLE=(Gamekey=GI_AttackStrong,Value=1.000000)
IK_Q=(Gamekey=GI_UseAbility,Value=1.000000)
IK_R=(Gamekey=GI_UseItem,Value=1.000000)
IK_RightMouse=(Gamekey=GI_AttackStrong,Value=1.000000)
IK_S=(Gamekey=GI_AxisLeftY,Value=-1.000000)
IK_Space=(Gamekey=GI_Accept_Evade,Value=1.000000)
IK_Up=(GameKey="GI_Up",Value=1)
IK_V=(Gamekey=GI_Adrenaline,Value=1.000000)
IK_W=(Gamekey=GI_AxisLeftY,Value=1.000000)
IK_Z=(Gamekey=GI_Medallion,Value=1.000000)
[MouseInput]
KeyboardCooldownSpeed=0.1
MouseDampX=7000
MouseDampY=7000
MouseSensitivityX=0.607692
MouseSensitivityY=0.379808
MouseSmoothness=0
SensitivityX=0.5
SensitivityY=0.5
Smoothness=0
UseMouseDamp=false
[Rendering]
AllowAntialias=1
AllowBloom=0
AllowBlur=0
AllowCutsceneDOF=0
AllowDOF=0
AllowDecals=0.5
AllowMotionBlur=0
AllowRain=0
AllowSSAO=0
AllowScatterDOF=0
AllowShafts=0
AllowSharpen=1
AllowVignette=1
AtlasTextureDownscale=0
DanglesLimiter=0
DetailTextureDownscale=0
Fullscreen=1
MaxAtlasTextureSize=2048
MaxCubeShadowCount=1
MaxCubeShadowSize=256
MaxSpotShadowCount=3
MaxSpotShadowSize=512
MaxTextureSize=2048
MeshDistanceScale=0.9
ShadowQuality=0
ShadowedLights=0
TextureDownscale=0
TextureMemoryBudget=400
UberSampling=0
VSync=0
[Sound]
MusicVolume=0.461538
[Viewport]
Height=768
Width=1360
Into a .txt file, save it as User.ini (all file types when saving) and copy it over the one you have, it might just be corrupted.
Actually, looking at the error it might just be a [ has been deleted from [Engine] so add that back in and save first
