This seems to happen maybe every 6 months or so. The table namespace suddenly goes missing.
Then backups were not working. Tried to do an export of the database but end up with exit code 2. Luckily I have a duplicate system to do testing. Ended up I deleted the table itemmaster2 (sql workbench had a problem opening it) (Also it was no longer in use from the last table corrupted accident which the programmer changed the code to take from itemaster3 instead of itemmaster2). I exported itemmaster3 from the demo server duplicate then I dropped the table on the production server. As item master only imports entries it was safe to drop all the data in the table it only needs the table structure to run. After that I tried sqlmyworkbench export data and mysqlbackupFTP which both complete dumping without problem. The lesson to learn here seems to be when tablename space goes missing and the table is still there. Drop the table and import in the table from the backup. Also if tables are unable to open or have some problem sql dump also seems to stop you from exporting.