Plugin "block/ratecourse" is defective or outdated, can not continue, sorry.
More information about this error
Debug info: Missing main block class file.
line 635 of /lib/upgradelib.php: plugin_defective_exception thrown
line 273 of /lib/upgradelib.php: call to upgrade_plugins_blocks()
line 1466 of /lib/upgradelib.php: call to upgrade_plugins()
line 317 of /admin/index.php: call to upgrade_noncore()