The first error happens when EGroupware tries to give you the error happening while setting the vacation message.
The second is a Warning happening when we try to parse the existing Sieve script.
Are you sure your IMAP server supports Sieve?
Stefan asked you that questions before, but no answer from you?
Does our mail account wizzard detects your server supporting Sieve?
Sieve filtering and vacation notices is nothing EGroupware can do without your IMAP server / provider supporting it!