Integer overflow detected while brute forcing

[matt99]

I get the error message:
Integer overflow detected in keyspace of mask: ?a?a?a?a?a?a?a?a?a?a?a

when i try tu bruteforce the md5 hash of a password, which is 11 chars (alphanumeric with special character)

Code:

hashcat -m 0 -a 3 the_md5-hash_of_a_11_provide_long_password ?a?a?a?a?a?a?a?a?a?a?a

Where is the mistake in my syntax? Is the keyspace too long for a bruteforce? That would be weird but the only possibility which I can imagine with those error messages. Thanks in advice.