A stack trace when the exception is raised should help to narrow down the problem:
https://sogo.nu/support/faq/how-do-i-debug-sogo.html

Thank you for reply.
I did a trace, thank you tfu for pointing me to that web page, and the result is:

May 28 16:31:45 sogod [1506]: |SOGo| starting method 'POST' on uri '/SOGo/Microsoft-Server-ActiveSync?User=epos2test@epos.cd.cz&DeviceId=QC355KOF8T3RT53G15BN5VM6VG&DeviceType=iPhone&Cmd=Search'
2018-05-28 16:31:45.996 sogod[1506] PG0x0x555555cd7bb0 SQL: SELECT count() FROM sogo_cache_folder_epos2test_A_epos_D_cd_D_cz
2018-05-28 16:31:46.049 sogod[1506] PG0x0x555555e63350 SQL: SELECT FROM sogo_view_default WHERE (LOWER(c_cn) LIKE '%chadima%' OR LOWER(mail) LIKE '%chadima%')

Breakpoint 1, -[NSException raise] (self=0x555555f62ac0, _cmd=0x7ffff5855b60 <_OBJC_SELECTOR_TABLE+384>) at NSException.m:960
960 NSException.m: No such file or directory.

That last line is really interesting a it obviously causing an error, but I am not sure what file or directory is sogod looking for?

this is the backtrace result:
https://pastebin.com/raw/VBsjqe4P

but after reading all that text I still can't tell what is that magic file sogod is missing.

I am new to debuging with gdp so I'm sorry if I'm missing something.

Thank you for Your time

What is the result of the query on sogo_view_default. According to the exception the problem happens when processing "telephonenumber".

Just out of curiosity, how did you found out that this exception happens when processing telephone number.

I tested search for LDAP entry without telephonenumber and it came out without an error. So I suppouse that wrong is in LDAP search result where by mistake result containing multiple phone numbers (2) and the second one is only international prefix (+420) and nothing else.

It seem that is the problem. I can say that this error was very hard to find. Thank you tfu for a great help.

From backtrace:
0000006 0x00007fffe7f81d15 in -[SOGoActiveSyncDispatcher processSearchGAL:inResponse:] (self=0x555555e90ae0,
_cmd=0x7fffe81bbe50 <_OBJC_SELECTOR_TABLE+3120>, theDocumentElement=0x555555ecf860, theResponse=0x555555e63a50)
at SOGoActiveSyncDispatcher.m:2906 <<< at this line the attribute telephonenumber is processed

Solved. It was really a telephonenumber attribute.

A special thanks to @tfu who taught me a bit more about debugging.