Mac OS X is one of the highly optimized, well secured operating system that offers various of advance features to its users. But, in some circumstances, user have to face couldn't validate source error 254. It generally appears, when someone tries to restore thumb drive or USB drives in Mac system. Now, you are thinking of the reasons that why such sorts of cumbersome situation takes place in midway? Is it not? If your answer is definitely yes. Then, you are at the right place. There are various of methods that are behind the emergence of couldn't validate source error 254. The most common among them is the corruption of internal file system. Beside that, if your are running over wrong ISO files then, also such sorts of annoying error messages appears.
Now, due to this issue you might have to loss some of your important files or data. Hence, make use of inbuilt “disk utility” to fix couldn't validate source error 254 and to pretend its working. However, if you still faces the same issue and its result in data loss situation. Then, without any further delay lets make use of third party Mac data recovery software. Its high end recovery feature and advance algorithm will completely scan and repair all your corrupted or lost Mac files including ISO files.