How can avoid following errors using MATLAB R2017a?

Hello, when l run a code I got this error in the function code given below. I don't know where this error is.

Error using fread
Invalid file identifier. Use fopen to generate a valid file identifier.

Error in loadDepthMap>readHeader (line 57)
     numFrames = typecast(uint8(fread(fid,4)), 'uint32');

Error in loadDepthMap (line 34)
[dims, numFrames] = readHeader(fid);

code:

function [depthMap] = loadDepthMap(path)
%%READING FROM FILE  
fid = fopen(path); %Assign file reading object 
[dims, numFrames] = readHeader(fid);
fileData = fread(fid, 'uint32');
fclose(fid); %close the stream  
depth = double(fileData); %convert to double for imaging  
depthCountPerMap = prod(dims);
depthMap = cell(1,numFrames);
for i=1 : numFrames
        currentDepthData = depth(1:depthCountPerMap);
    depth(1:depthCountPerMap) = [];
    depthMap{i} = reshape(currentDepthData, dims(1), dims(2))'; %reshape depth into matrix

end

end  

function [dims,numFrames] = readHeader(fid)

       numFrames = typecast(uint8(fread(fid,4)), 'uint32');
       dims(1) = typecast(uint8(fread(fid,4)), 'uint32');
       dims(2) = typecast(uint8(fread(fid,4)), 'uint32');
  end

[KSSV]

The error says fread is unable to get the exact file or file location. Check to it that file is existing int he given path.

[Freceena Francis]

Thank You .. It really worked...