. My debug:

Apr 09 09:13:20 imap(pid 82675 user test1): Debug: acl vfile: file /Library/Server/Mail/Config/dovecot/global-acls/INBOX not found
Apr 09 09:13:20 imap(pid 82675 user test1): Debug: acl vfile: file /Library/Server/Mail/Data/mail/EB83247B-1A33-4A43-AD30-E6453789072A/dovecot-acl not found
Apr 09 09:13:20 imap(pid 82675 user test1): Debug: acl vfile: file /Library/Server/Mail/Config/dovecot/global-acls//.DEFAULT not found
A

Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Added userdb setting: mail=maildir:/Library/Server/Mail/Data/mail/EB83247B-1A33-4A43-AD30-E6453789072A
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Added userdb setting: mail_location=maildir:/Library/Server/Mail/Data/mail/EB83247B-1A33-4A43-AD30-E6453789072A
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Added userdb setting: plugin/master_user=mailmaster
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Added userdb setting: plugin/quota=maildir:User quota
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Added userdb setting: plugin/quota_rule=*:storage=5120
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Added userdb setting: plugin/sieve=/Library/Server/Mail/Data/rules/EB83247B-1A33-4A43-AD30-E6453789072A/dovecot.sieve
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Added userdb setting: plugin/sieve_dir=/Library/Server/Mail/Data/rules/EB83247B-1A33-4A43-AD30-E6453789072A
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Added userdb setting: plugin/sieve_storage=/Library/Server/Mail/Data/rules/EB83247B-1A33-4A43-AD30-E6453789072A
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Effective uid=214, gid=6, home=
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Quota root: name=User quota backend=maildir args=
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Quota rule: root=User quota mailbox=* bytes=5242880 messages=0
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Quota warning: bytes=5242880 (100%) messages=0 reverse=no command=quota-exceeded test1
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Quota warning: bytes=4194304 (80%) messages=0 reverse=no command=quota-warning test1
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Quota grace: root=User quota bytes=524288 (10%)
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Namespace inbox: type=private, prefix=, sep=, inbox=yes, hidden=no, list=yes, subscriptions=yes location=maildir:/Library/Server/Mail/Data/mail/EB83247B-1A33-4A43-AD30-E6453789072A
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: maildir++: root=/Library/Server/Mail/Data/mail/EB83247B-1A33-4A43-AD30-E6453789072A, index=, indexpvt=, control=, inbox=/Library/Server/Mail/Data/mail/EB83247B-1A33-4A43-AD30-E6453789072A, alt=
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl: initializing backend with data: vfile:/Library/Server/Mail/Config/dovecot/global-acls:cache_secs=300
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl: acl username = mailmaster
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl: owner = 0
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl vfile: Global ACL legacy directory: /Library/Server/Mail/Config/dovecot/global-acls
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Namespace acl-mailboxes: type=shared, prefix=shared.%u., sep=., inbox=no, hidden=no, list=children, subscriptions=no location=maildir:/Library/Server/Mail/Data/mail/users/%u:INDEX=/Library/Server/Mail/Data/mail/shared/%u
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: shared: root=/var/run/dovecot, index=, indexpvt=, control=, inbox=, alt=
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl: initializing backend with data: vfile:/Library/Server/Mail/Config/dovecot/global-acls:cache_secs=300
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl: acl username = mailmaster
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl: owner = 0
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl vfile: Global ACL legacy directory: /Library/Server/Mail/Config/dovecot/global-acls
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: Namespace list-archives: type=shared, prefix=archives.%u., sep=., inbox=no, hidden=no, list=children, subscriptions=no location=maildir:/Library/Server/Mail/Data/listserver/messages/archive/lists/%u:INDEX=/Library/Server/Mail/Data/listserver/messages/archive/shared/%u
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: shared: root=/var/run/dovecot, index=, indexpvt=, control=, inbox=, alt=
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl: initializing backend with data: vfile:/Library/Server/Mail/Config/dovecot/global-acls:cache_secs=300
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl: acl username = mailmaster
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl: owner = 0
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: acl vfile: Global ACL legacy directory: /Library/Server/Mail/Config/dovecot/global-acls
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: fts: Indexes disabled for namespace 'shared.'
Apr 09 09:13:06 imap(pid 82675 user test1): Debug: fts: Indexes disabled for namespace 'archives.'



Am 09.04.2019 um 08:43 schrieb Aki Tuomi <aki.tuomi@open-xchange.com>:


On 9.4.2019 9.41, Ludwig Wieland via dovecot wrote:
Hello,

My  Dovecot Master can login but not not select INBOX !
What's wrong   ?

best regards
Luda



1) USER can select INBOX:    OK
---------------------------------------------------
telnet localhost imap
Trying ::1...
Connected to localhost.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS AUTH=CRAM-MD5 AUTH=DIGEST-MD5 AUTH=GSSAPI AUTH=PLAIN AUTH=LOGIN] Dovecot ready.
a login test1 password           
a OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS BINARY MOVE SEARCH=FUZZY SPECIAL-USE COMPRESS=DEFLATE QUOTA ACL RIGHTS=texk] Logged in
b select INBOX
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft \*)] Flags permitted.
* 5 EXISTS
* 0 RECENT
* OK [UNSEEN 1] First unseen.
* OK [UIDVALIDITY 1328091893] UIDs valid
* OK [UIDNEXT 6] Predicted next UID
* OK [HIGHESTMODSEQ 11] Highest
b OK [READ-WRITE] Select completed (0.000 + 0.000 secs).
c logout
* BYE Logging out
c OK Logout completed.
Connection closed by foreign host.

2) MASTER-USER can't select INBOX:  !
---------------------------------------------------
admins$ telnet localhost imap
Trying ::1...
Connected to localhost.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS AUTH=CRAM-MD5 AUTH=DIGEST-MD5 AUTH=GSSAPI AUTH=PLAIN AUTH=LOGIN] Dovecot ready.
a login test1*mailmaster password
a OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS BINARY MOVE SEARCH=FUZZY SPECIAL-USE COMPRESS=DEFLATE QUOTA ACL RIGHTS=texk] Logged in
b select INBOX
b NO [SERVERBUG] Internal error occurred. Refer to server log for more information. [2019-04-09 08:20:46] (0.000 + 0.000 secs).
c logout
* BYE Logging out
c OK Logout completed.
Connection closed by foreign host.

----------------------------------------
An the Server Error log says:
Apr 09 00:05:40 imap(pid 62335 user test1): Error: Opening INBOX failed: Mailbox doesn't exist: INBOX
----------------------------------------

Can you turn on mail_debug=yes, restart dovecot, try again and post the
logs?

Aki