Sometime due to problem in internal Mac file system, user have to face Mac filevault "no mountable file systems". Further, apart from internal error, there are various of other reasons too that are quite responsible for the Mac filevault "no mountable file system" like installation of some unmountable files or unsupported apps, incomplete removal of Mac files, sudden power surge while Mac files are in use, might be due to installation of unknown applications, etc. But, you don't have to be worried! As its quite possible to fix Mac filevault "no mountable file system" error. Well, to rescue no mountable file system error, what you have to do is to simply make use of Disk utility. The tool is well featured with reliable techniques, which scan and fix your hard drive issue. However, if you fail to get rid of Mac filevault "no mountable file system" error, then don't worry! Move to next step i.e. make use of Mac Terminal and write the command;
hdiutil attach -nomount -noverify -ignorebadchecksums /path/to/faulty.sparsebundle
However, if the problem is still be there, then the last option for left with you is go for re-installation of Mac OS X. But, doing so will erase all your saved files. Hence, in such situation it make use of third party Mac data recovery software to rescue lost Mac files.