How to fix Flashing Folder with a Question Mark on My Macbook pro?

Since you were using macOS 10.13.6 on the internal SSD, then it means the APFS file system is being used so macOS 10.11 El Capitan is useless for trying to repair or access the contents of the SSD now. You can try booting into Internet Recovery Mode using Command + Option + R to attempt to access the online macOS 12.x Monterey installer. Unfortunately some Macs will only boot into the online installer for the OS which originally shipped with the Mac from the factory no matter the keys used for booting.

You cannot trust the results of First Aid from macOS 10.11 here since the drive should be using the newer drive layout & file system.

While booted to a macOS 10.13+ installer you may need to click "View" within Disk Utility and select "Show All Devices" before the physical drive and hidden Container appear on the left pane of Disk Utility. Select the physical drive to scan first, then scan the hidden Container which will also scan all APFS volumes located within it. Even if First Aid says everything is "Ok", click "Show Details" and scroll back through the report to see if any unfixed errors are listed. If there are any unfixed errors listed, then run First Aid again to see if they have been repaired. If the errors cannot be repaired, then you won't be able to fix the boot issue until you erase the whole physical SSD followed by reinstalling macOS & restoring from a backup. Erasing the disk will destroy all data on the SSD.

If you need to retrieve data from the SSD, then I would recommend installing macOS 10.13 High Sierra to an external USB3 drive so you can try using a data recovery app to attempt to recover your data while booted from the external drive. I have seen Stellar Data Recovery recommended on this forum previously. You can begin by installing macOS 10.11 to the external drive, then later installing macOS 10.13....avoid installing macOS 10.14+ since they will require updating the system firmware which requires a working internal SSD which you don't have at the moment. You can find links to various macOS installers in this Apple article:

How to download and install macOS - Apple Support

The main thing is to make sure you erase the external drive and select the external drive for the OS install. If you accidentally erase the internal SSD, then the data is instantly & permanently gone.

If you have a bootable macOS external drive, then you can also check the health of the internal SSD by running DriveDx (free trial period) and posting the complete text report here using the "Additional Text" icon which looks like a piece of paper so I can review it. It is also possible to check the health of the internal Apple SSD by using a Linux boot disk...I can provide instructions if necessary. Unfortunately Apple blade style SSDs have very little health information, but it never hurts to check since it may help understand what occurred.

What OS are you booting into when booting into Recovery Mode? It is the OS listed for "Install macOS xxxxxx".

Is this laptop using an original Apple OEM SSD or a third party SSD? If so, then you need to boot into macOS 10.13+ before you can see a third party NVMe based internal SSD. Try booting into Internet Recovery Mode using Command + Option + R to attempt to access the macOS 12.x Monterey online installer. Within Disk Utility click "View" and select "Show All Devices" so that the physical SSD appears on the left pane of Disk Utility. If the physical SSD still does not appear, then you likely have a bad SSD.

If you are using a third party M.2 internal SSD, then it could be a bad or incompatible SSD adapter.

If it is a third party SSD, what is the make & model of the internal SSD? And if it is an M.2 SSD, then the make & model of the SSD adapter?

AleGallo93 wrote:

sorry what do you mean by: "Is this laptop using an original Apple OEM SSD or a third party SSD? If so, then you need to boot into macOS 10.13+ before you can see a third party NVMe based internal SSD. "

And then: "If you are using a third party M.2 internal SSD, then it could be a bad or incompatible SSD adapter.

"If it is a third party SSD, what is the make & model of the internal SSD? And if it is an M.2 SSD, then the make & model of the SSD adapter?" ??

If you don't know what this means, then you have not replaced the original Apple SSD with a third party replacement/upgrade SSD. However, if you purchased this laptop used, then the previous owner may have installed a third party non-Apple SSD into the laptop.

A third party non-Apple SSD will only be recognized when booting from macOS 10.13+.

If you do not have a third party non-Apple SSD installed internally, then you can ignore that section of my previous post as it would not apply.

AleGallo93 wrote:

Hello, I need your help.

My macbook pro 13" early 2015 shows a folder with a question mark and won't boot. From macOS Recovery the disk utility does not seem to find the boot disk so I cannot perform the first aid. What other solutions can I try before turning to a professional data recovery company?

Any suggestions will be helpful

If your Mac starts up to a question mark

If your Mac starts up to a question mark - Apple Support

If you value your user data

3-2-1 Backup Strategy: three copies of your data, two different methods, and one offsite.

More than one device, more than one backup methodology.

That is an original Apple OEM SSD.