Error messages

1^st ERROR - Lightroom encountered an error when reading from its preview cache and needs to quit. Lightroom will attempt to fix this problem the nex time it launches.

2^nd ERROR – An internal error has occurredLightroom_Fatal_SQLite_Transient_Error :: Dadtabase: F:\Lightroom2013\Lightroom 3 Catalog. Ircat :: Error: disk I/O error :: SQL: SELECT id_local FROM Adobe_images WHERE id_local = ?;