This word is acceptable for play in the UK dictionary that is being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. The property of being impossible to read.

n. The property of being unfit for reading.

"As a theme, in other words, unreadability is thoroughly readable, and is thus, paradoxically, a comforting distraction from the actual puzzles and discontinuities that reading, as a praxis, endlessly encounters."

unreliability   

inscrutability    indecipherability    illegibility