Source: The Great Interpretation of Dreams (Ibn Sirin)
Praying facing away from the Qibla indicates committing a great sin, misguidance in religion, or abandoning the Sunnah.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
Praying facing away from the Qibla indicates Hajj if it is during the Hajj months, or indicates confusion in religion.
Source: Signs in the Science of Expressions (Ibn Shaheen)
Praying facing away from the Qibla is interpreted as committing a major mistake or misguidance.