Before with Mathematica 11.0.1.0 my CUDA was working fine. Now with Mathematica 11.1.0.0, CUDAFunctionLoad gives errors. Take this simple example from Mathematica documentation:

Needs["CUDALink`"]
code = "
  __global__ void addTwo(mint * in, mint * out, mint length) {
    int index = threadIdx.x + blockIdx.x*blockDim.x;
    if (index < length)
     out[index] = in[index] + 2;
  }";
cudaFun = 
 CUDAFunctionLoad[code, 
  "addTwo", {{_Integer, _, "Input"}, {_Integer, _, 
    "Output"}, _Integer}, 256]

This is gives issues with StringJoin, StringTrim and an internal error

CCompilerDriver`CCompilerDriverBase`InvokeCompiler::cmdstr: An internal error occurred while generating compilation commands. The InputForm of the generated command list is StringTrim[StringJoin["\n\n", CCompilerDriver`CCompilerDriverBase`BaseDriver["CreateExecutableCommands"][CUDAFunctionLoad, <<20>>, {"CreateBinary" -> True, "CUDAArchitecture" -> {}, "Defines" -> {"USING_CUDA_FUNCTION" -> 1, <<2>>, "USING_DOUBLE_PRECISIONQ" -> 1}, <<17>>, "XCompilerInstallation" -> Automatic}], "\n"]]

CUDAFunctionLoad::cmpf: The kernel compilation failed. Consider setting the option "ShellOutputFunction"->Print to display the compiler error message.

This is with CUDA paclet 10.5.0 still based on the old CUDA 7.5.18 toolkit in stead of CUDA 8.0. Compiler is from Microsoft Visual Studio 2015 Community Edition. OS is Windows 10. nVIDIA driver is latest 378.78 with CUDA 8.0 in the driver.

Update 27/03/2017:

In the meantime I also have Mathematica 11.1.0.0 running in CentOS 7.3 x86_64 linux with gcc 4.8 as compiler and latest nVIDIA driver 375.39. I can confirm the same string errors happen. It seems internal Mathematica processing that goes wrong.