Seem to me that worked fine before upgrade, and works after upgrade with Roundcube.
dovecot.log has not any logs line than I'm trying to logon win master user (email*master), but sogo.log with debug has:
May 20 15:40:24 sogod [29953]: |SOGo| starting method 'POST' on uri '/SOGo/connect'
May 20 15:40:24 sogod [29953]: <0x0x7f672febc3f8[SOGoCache]> Cache cleanup interval set every 300.000000 seconds
May 20 15:40:24 sogod [29953]: <0x0x7f672febc3f8[SOGoCache]> Using host(s) '127.0.0.1' as server(s)
May 20 15:40:24 sogod [29953]: |SOGo| traverse(acquire): SOGo => connect
May 20 15:40:24 sogod [29953]: |SOGo| do traverse name: 'SOGo'
May 20 15:40:24 sogod [29953]: |SOGo| do traverse name: 'connect'
May 20 15:40:24 sogod [29953]: [ERROR] <0x0x7f672ff6c858[NGBundleManager]> could not create bundle for path: '/usr/share/GNUstep/Libraries/gnustep-base/Versions/1.24/Resources/SSL.bundle'
May 20 15:40:25 sogod [29953]: [WARN] <0x0x7f672cc263c0[WOxElemBuilder]> could not locate builders: WOxExtElemBuilder,WOxExtElemBuilder
May 20 15:40:25 sogod [29953]: |SOGo| set clientObject: <SOGo[0x0x7f67301b1678]: name=SOGo>
May 20 15:40:25 sogod [29953]: <0x0x7f673052dee8[NGLdapConnection]> Using ldap_initialize for LDAP URL: ldap://127.0.0.1:389
May 20 15:40:25 sogod [29953]: <0x0x7f673052bbe8[NGLdapConnection]> Using ldap_initialize for LDAP URL: ldap://127.0.0.1:389
2016-05-20 15:40:25.010 sogod[29953] -[NGLdapConnection _searchAtBaseDN:qualifier:attributes:scope:]: search at base '' filter '(objectClass=*)' for attrs 'subschemaSubentry'
2016-05-20 15:40:25.013 sogod[29953] -[NGLdapConnection _searchAtBaseDN:qualifier:attributes:scope:]: search at base 'cn=Subschema' filter '(objectClass=*)' for attrs 'objectclasses'
2016-05-20 15:40:25.017 sogod[29953] -[NGLdapConnection _searchAtBaseDN:qualifier:attributes:scope:]: search at base 'o=domains,dc=domain,dc=tld' filter '(&(mail=user@domain.tld*sogo_sieve_master@not-exist.com)(objectClass=mailUser)(accountStatus=active)(enabledService=mail))' for attrs 'dn'
May 20 15:40:25 sogod [29953]: SOGoRootPage Login from '192.168.0.31' for user 'user@domain.tld*sogo_sieve_master@not-exist.com' might not have worked - password policy: 65535 grace: -1 expire: -1 bound: 0
May 20 15:40:25 sogod [29953]: |SOGo| request took 0.024878 seconds to execute
May 20 15:40:25 sogod [29953]: <0x0x7f672fee4a58[WOResponse]> Zipping of response disabled
May 20 15:40:25 sogod [29953]: 192.168.0.31 "POST /SOGo/connect HTTP/1.1" 403 34/122 0.027 - - 3M
May 20 15:40:25 sogod [29953]: |SOGo| terminating app, vMem size limit (128 MB) has been reached (currently 350 MB)
May 20 15:40:25 sogod [29943]: <0x0x7f673017f7d8[WOWatchDogChild]> child 29953 exited
May 20 15:40:25 sogod [29943]: <0x0x7f672fee12b8[WOWatchDog]> child spawned with pid 30010
2016-05-20 15:40:25.053 sogod[30010] MySQL4 connection established 0x0x7f67302911a0
2016-05-20 15:40:25.053 sogod[30010] MySQL4 channel 0x0x7f672ff2f778 opened (connection=0x0x7f67302911a0,sogo)
2016-05-20 15:40:25.053 sogod[30010] <MySQL4Channel[0x0x7f672ff2f778] connection=0x0x7f67302911a0> SQL: SELECT count(*) FROM sogo_user_profile;
2016-05-20 15:40:25.054 sogod[30010] <MySQL4Channel[0x0x7f672ff2f778] connection=0x0x7f67302911a0> query has results, entering fetch-mode.
2016-05-20 15:40:25.054 sogod[30010] <MySQL4Channel[0x0x7f672ff2f778] connection=0x0x7f67302911a0> SQL: SELECT count(*) FROM sogo_folder_info;
2016-05-20 15:40:25.054 sogod[30010] <MySQL4Channel[0x0x7f672ff2f778] connection=0x0x7f67302911a0> query has results, entering fetch-mode.
2016-05-20 15:40:25.056 sogod[30010] <MySQL4Channel[0x0x7f672ff2f778] connection=0x0x7f67302911a0> SQL: SELECT count(*) FROM sogo_sessions_folder;
2016-05-20 15:40:25.056 sogod[30010] <MySQL4Channel[0x0x7f672ff2f778] connection=0x0x7f67302911a0> query has results, entering fetch-mode.
2016-05-20 15:40:25.056 sogod[30010] <MySQL4Channel[0x0x7f672ff2f778] connection=0x0x7f67302911a0> SQL: SELECT count(*) FROM sogo_alarms_folder;
2016-05-20 15:40:25.057 sogod[30010] <MySQL4Channel[0x0x7f672ff2f778] connection=0x0x7f67302911a0> query has results, entering fetch-mode.