The mysql client prompts "Cannot proceed because system... "problem: the client prompts "Cannot proceed because system tables used by Event sched1_were found damaged at server start". This is because the current MySQL server version is not compatible with all databases. Finally, we will summarize the problem solution.: 1. Copy the mysql_upgrade.exeand mysqlcheck.exe files to the APMServ5.2.6 \ MySQL5.1 \ bin directory. 2. Click "start" --> "run", Enter "cmd", and press "Enter" to Enter the DOS command line window (if our APMServ is placed in the root directory of zone D) enter "D:", Press Enter, then Enter "cd APMServ5.2.6 \ MySQL5.1 \ bin", and press Enter ), enter export mysql_upgrade.exe-u root-p "(If your MySQL username is still root) and press Enter. Then, the doscommand line prompts" Enter password :", enter the MySQL password and press Enter to automatically upgrade the system table structure. 3. Stop APMserv and restart APMserv. The problem can be solved.