Change column name in MariaDB

If you are using dot (.) instead of table name that is why you have error. You have to specify table name:

ALTER TABLE `table_name` CHANGE COLUMN `Anzahl Personen` AnzahlPersonen int(11);

ALTER TABLE <table_name> CHANGE COLUMN old_name new_name column_definition

https://jira.mariadb.org/browse/MDEV-16290