Have you seen question mark folder when startup Mac? Are you in the search of the guidelines about this issue in the Mac computers. If yes then this is the exact place which you are looking for. This post will make you aware about the possible causes that results to question mark folder when startup Mac and what to do if you loss any data due to this issue. Well, its not a new issue in the Mac computers, other users are also gone through the same issue. The reasons behind the question mark folder when startup Mac is damaging or missing of the system software. If your Mac computer is infected with dangerous threat then also you may notice this issue. Sometimes conflict of third party software programs in the Mac computer and incompatibility of externals devices will also lead this problem. Corrupted PRAM is also one of the reason for question mark folder when startup Mac. In order to fix this issue you should try some manual steps like boot the system with extensions off, rebless the system folder, disconnect external devices, reset the PRAM. If this problem in your Mac computer causes loss of data then it is advised you to go with the Mac data recovery software.