Fatal error on activation

I’m getting the following error:

Plugin could not be activated because it triggered a fatal error.

Notice: Use of undefined constant wp_myplugin_property_title – assumed ‘wp_myplugin_property_title’ in /(…)/wp-content/plugins/levelfourstorefront/levelfourstorefront.php on line 813 Notice: Undefined index: HTTPS in /(…)/wp-content/plugins/levelfourstorefront/levelfourstorefront.php on line 26 Warning: fopen(/(…)/wp-content/plugins/levelfourstorefront/Connections/flashdb.php): failed to open stream: Permission denied in /(…)/wp-content/plugins/levelfourstorefront/levelfourstorefront.php on line 59 Warning: fwrite() expects parameter 1 to be resource, boolean given in /(…)/wp-content/plugins/levelfourstorefront/levelfourstorefront.php on line 60 Warning: fclose() expects parameter 1 to be resource, boolean given in /(…)/wp-content/plugins/levelfourstorefront/levelfourstorefront.php on line 61 Warning: require_once(/(…)/wp-content/plugins/levelfourstorefront/Connections/flashdb.php): failed to open stream: No such file or directory in /(…)/wp-content/plugins/levelfourstorefront/levelfourstorefront.php on line 64 Fatal error: require_once(): Failed opening required ‘/(…)/wp-content/plugins/levelfourstorefront/Connections/flashdb.php’ (include_path=’.:/usr/share/php:/usr/share/pear’) in /(…)/wp-content/plugins/levelfourstorefront/levelfourstorefront.php on line 64