I recently encountered this error on Disposeamail - a free disposable email site of mine that uses MySQL heavily for storing all incoming mail through an email pipe script.
I did a lot of researching, and basically, there are a few primary culprits I was able to identify that will hopefully save you some time.
MySQL will produce this error sometimes when the temp directory is not writeable.
This step ONLY APPLIES IF THE ABOVE STEPS DID NOT WORK.
Read the MySQL Manual page on removing InnoDB log files for a safer backup and restoration procedures. Basically, the steps are:
My specific problem was that somehow the “skip-innodb” line got added back into my “my.cnf” file, so MySQL was expecting a different table format when loading data. I suspect this had something to do with my cPanel/WHM setup overwriting the file, but I’ll never know for sure.