On a Macbook during the start-up process, a number of system checks are done. While the Macbook is doing that you will see the screen change colors and one of a few icons pop up. Once in a while more than one may show up. These icons help show that the Macbook will either start-up correctly or what happened if something went wrong. The different icons that can show up are the gray apple logo, a happy mac, flashing question mark, prohibitory sign, flashing folder or a flashing globe. The happy mac icon will only appear on older macs running OS 9 or earlier. If you have a flashing folder icon on the screen instead of a gray apple logo then that is indicating that an error has occurred during the start-up process.
If the flashing folder icon does appear during the start-up process, there are a lot of possible causes for it to happen. The main causes of it are certain system files were erased, moved to another location, or are corrupt. Usually this particular error is caused by something that may have accidentally deleted some important system files or moved them to another location. Sometimes another application or process might cause either a system file to be corrupted or some system settings to be changed to an invalid entry. There are other causes which are not very common and usually require a complex set of conditions to trigger them.
There are some troubleshooting steps that can resolve any issues regarding the flashing folder icon. The first troubleshooting step that is highly recommended for this and many other technical issues is to power the Macbook off for at least 30 seconds then turn it back on. If this does not resolve the issue then it would be best to let an Apple Certified technician at Mac Repairs London (www.macrepairslondon.com) take a look at it and further troubleshoot the issue.