Q: MacBookPro stuck on sign in page!

What year/model of MacBook Pro are you using?

What OS X are you running?

See this technote: About the screens you see when your Mac starts up - Apple Support

Kim

Try starting in Safe Mode.

     1. Start or restart your Mac.

     2. Immediately after you hear the startup sound, press and hold the Shift key.

     3. Release the Shift key when you see the Apple logo appear on the screen.

If that does not work, try starting in recovery mode.

Startup key combinations for Mac - Apple Support

Try reseting SMC. Reset the System Management Controller (SMC) on your Mac - Apple Support

Try reseting NVRAM. How to Reset NVRAM on your Mac - Apple Support

Another possibility is that your problem may be a failing hard drive or the hard drive SATA cable.

MacBook Pro 13" Mid 2012 Hard Drive Cable Symptoms: Symptoms

MacBook Pro hard drive SATA cable issue. MacBook Pro Hard Drive Cable Failure-Free fix and preventative maintenance

MacBook Pro blinking question mark issue. MacBook Pro Question Mark Issue

If your SATA cable is faulty, here is a guide on how to replace it.

MacBook Pro 13" Unibody Late 2011 Hard Drive Cable Replacement: iFixit.com

MacBook Pro 13" Unibody Late 2011 Hard Drive Cable: SATA Cable

To test whether the problem is your hard drive or SATA cable:

You can remove your hard drive from Mac and install in an external enclosure OWC external case or using a USB to SATA adapter USB to SATA adapter and connect it to your MBP via USB. And then try to boot from it using Startup Manager. This will help to identify if your hard drive or SATA cable are at fault. If it boots the MBP, most likely the problem will be the drive SATA cable needs to be replaced.

Kim

That is very odd.

From the guest account try starting Disk Utility and running first aid.

Kim