The Maria storage engine is not supported for virtual columns:

mysql> CREATE TABLE IF NOT EXISTS X ( f1 INTEGER, v1 integer AS (f1) VIRTUAL ) engine=Maria;
ERROR 1646 (HY000): 'Specified storage engine' is not yet supported for computed columns

Also, the error message could be improved, at least to include the name of the storage engine in question ( in case it is not specified as part of the CREATE TABLE statement, but instead comes from a server-wide or a session default).