I met the following issue a few weeks back. I noticed that my SSD was full so I wanted to delete some of my useless data to free up space. For some reason after deleting the files I could not empty the trash.
I thought it must be some kind of bug so I rebooted my computer. After reboot the booting process stopped at loading the Ubuntu logo. I had to reinstall the whole system. Does anyone know what could cause it and how can I prevent such things?