Sessions - woran liegt es?

[chichi]

Bekomme folgende Meldung beim Aufruf von Sessions:

Warning: Unknown(): The session id contains invalid characters, valid characters are only a-z, A-Z and 0-9 in Unknown on line 0

Warning: Unknown(): Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0

woran liegt es?

chiChi