Full ERROR Message Example:
ERROR [SharedPool-Worker-1] XXXX-XX-XX XX:XX:XX,XXX QueryProcessor.java:578 - The statement:  could not be parsed.
What does this ERROR message mean?
Cassandra uses a parser called ANTLR to parse CQL statements as a safety net. If the parsing fails in an unpredictable way the code will catch the error and log it as per the example message above.
Why does this ERROR occur?
This errors can occur due to incorrectly formed CQL statements.
How do you fix this ERROR?
You will need to review the specific error reported and take a closer inspection at the query that could not be parsed to determine if it's a badly formed CQL statement.