Hello, our dovecot mailservice was running smoothly for a long time. Since last week we get the following error message when connecting from the horde/imp webmailer to the public namespace: Panic: file acl-cache.c: line 294 (acl_cache_update): assertion failed: (obj_cache->my_current_rights != &negative_cache_entry) Dovecot and horde/imp are running on seperate hosts. There are no known recent configuration changes, neither on the webmailer nor on the dovecot host. Helga dovecot -n # 1.2.17: /etc/dovecot.conf # OS: Linux 2.6.18-238.9.1.el5 x86_64 Scientific Linux SL release 5.5 (Boron) listen(default): 192.168.0.104:143 127.0.0.1:143 144.41.4.87:143 listen(imap): 192.168.0.104:143 127.0.0.1:143 144.41.4.87:143 listen(pop3): *:110 ssl_listen(default): 144.41.4.28:993 ssl_listen(imap): 144.41.4.28:993 ssl_listen(pop3): 144.41.4.28:995 ssl_cert_file: /etc/ssl/certs/imapd.pem ssl_key_file: /etc/ssl/certs/imapd.pem disable_plaintext_auth(default): no disable_plaintext_auth(imap): no disable_plaintext_auth(pop3): yes login_dir: /var/run/dovecot/login login_executable(default): /usr/libexec/dovecot/imap-login login_executable(imap): /usr/libexec/dovecot/imap-login login_executable(pop3): /usr/libexec/dovecot/pop3-login login_max_processes_count: 2048 max_mail_processes: 2048 first_valid_uid: 200 mail_drop_priv_before_exec(default): yes mail_drop_priv_before_exec(imap): yes mail_drop_priv_before_exec(pop3): no mail_executable(default): /afs/hoh/common/etc/mail/bin/acl-groups mail_executable(imap): /afs/hoh/common/etc/mail/bin/acl-groups mail_executable(pop3): /usr/libexec/dovecot/pop3 mail_process_size: 1024 mail_plugins(default): acl imap_acl lazy_expunge metadata imap_annotatemore mail_log mail_plugins(imap): acl imap_acl lazy_expunge metadata imap_annotatemore mail_log mail_plugins(pop3): lazy_expunge mail_log mail_plugin_dir(default): /usr/lib64/dovecot/imap mail_plugin_dir(imap): /usr/lib64/dovecot/imap mail_plugin_dir(pop3): /usr/lib64/dovecot/pop3 mail_log_max_lines_per_sec: 0 imap_client_workarounds(default): tb-extra-mailbox-sep imap_client_workarounds(imap): tb-extra-mailbox-sep imap_client_workarounds(pop3): namespace: type: private separator: / location: maildir:/maildir/%1n/%u:LAYOUT=fs inbox: yes list: yes subscriptions: yes namespace: type: private separator: / prefix: .EXPUNGED/ location: maildir:/maildir/expunged/%1n/%u:LAYOUT=fs hidden: yes list: no subscriptions: yes namespace: type: shared separator: / prefix: Shared/%%u/ location: maildir:/maildir/%%1n/%%u:LAYOUT=fs list: children namespace: type: public separator: / prefix: Groups/ location: maildir:/maildir/public:LAYOUT=fs list: children namespace: type: public separator: / prefix: .G-EXPUNGED/ location: maildir:/maildir/expunged/public:LAYOUT=fs hidden: yes list: no subscriptions: yes lda: postmaster_address: postmaster at uni-hohenheim.de mail_plugins: acl auth default: mechanisms: plain login verbose: yes debug: yes passdb: driver: pam userdb: driver: passwd socket: type: listen client: path: /var/spool/postfix/private/auth mode: 432 user: postfix group: postfix master: path: /var/spool/postfix/private/auth-master mode: 384 user: postfix group: postfix plugin: mail_log_events: delete undelete expunge copy mailbox_delete mailbox_rename mail_log_group_events: mail_log_fields: uid box msgid size acl: vfile acl_shared_dict: proxy::acl_dict lazy_expunge: .EXPUNGED/ metadata_dict: proxy:/var/run/dovecot/dict-server:metadata dict: acl_dict: mysql:/etc/dovecot-dict-sql.conf metadata: sqlite:/etc/metadata-dict.conf -- This smoke signal communication (and any attachment/s) is confidential and intended only for the individual(s) or entity named above and to others who have been specifically authorized to receive it. If you are not the intended recipient, please do not read, copy, use or disclose the contents of this communication to others. Please notify the sender that you have received this smoke signal in error, by calling the phone number indicated or by smoke signals, and stamp out the fire (including any attachment/s) subsequently. Thank you.