How to fix error 36 on Mac? It is one of the common question asked by most of the Mac user. However Mac is considered to be the safest computer but it doesn’t mean that you will not face issue on it. The error usually occurs when user try to copy data to some external hard drive. Occurrence of this error message interrupt the data transfer process. As a result the copied files are not in proper state and the biggest worry is you can end up losing vital data if you don’t pay attention.