Not sure what else to tell you. The error is because it could not open one of the shared memory files. It'd be nice if the error was changed to show the filename, but you could find that out by running it in the debugger if you like.
Code:
MemoryMappedFile::MemoryMappedFile(std::string filename)
: filename_(filename) {
imp_ = new Implementation;
//get existing size
FILE *f = fopen(filename.c_str(), "rb");
if(!f) {
EQ_EXCEPT("Shared Memory", "Could not open the file to find the existing file size.");
}