Docbase creation fails on 16.4 running on RHEL 7.6

Hi Team,

We are trying to setup new Documentum 16.4 content server on Rhel 7.6, During docbase creation we are getting below error.

Opentext says is Documentum 16.4 not unsupported with RHEL 7.6. Any successful installation on RHEL 7.5 or above ?.

Error in docbase log.

Thu Dec 20 15:54:24 2018[DM_STARTUP_W_DOCBASE_OWNER_NOT_FOUND] *** warning *** : The database user, Docbase as specified by your server.ini is not a valid user as determined using the system password check api. This will likely severly impair the operation of your docbase.

OpenText Documentum Content Server (version 16.4.0070.0119 Linux64.Oracle)
Copyright (c) 2018. OpenText Corporation
All rights reserved.
2018-12-20T15:54:24.565960 11154[11154] 0000000000000000 [DM_SERVER_I_START_SERVER]info: "Docbase Docbase attempting to open"

2018-12-20T15:54:24.566099 11154[11154] 0000000000000000 [DM_SERVER_I_TRACING_ENABLED_GLOBAL]info: "Tracing type: 'sqltrace'"

2018-12-20T15:54:24.566153 11154[11154] 0000000000000000 [DM_SERVER_I_START_KEY_STORAGE_MODE]info: "Docbase Docbase is using database for cryptographic key storage"

2018-12-20T15:54:24.566179 11154[11154] 0000000000000000 [DM_SERVER_I_START_SERVER]info: "Docbase Docbase process identity: user(dctmdev)"

2018-12-20T15:54:24.566221 11154[11154] 0000000000000000 In disArmSIGPIPEForDBConnection: prev_disp = 0x0

2018-12-20T15:54:24.669635 11154[11154] 0000000000000000 [SQL] -1 LOGON 0.0906410000
2018-12-20T15:54:24.669908 11154[11154] 0000000000000000 [SQL] -1 select sid from v$session where audsid = userenv('sessionid')
2018-12-20T15:54:24.672777 11154[11154] 0000000000000000 [SQL] -1 EXEC 0.0030020000
2018-12-20T15:54:24.672908 11154[11154] 0000000000000000 [SQL] 6646 FETCH(0) 0.0000840000
2018-12-20T15:54:24.673018 11154[11154] 0000000000000000 In armSIGPIPEForDBConnection: SIGPIPE is not Armed

2018-12-20T15:54:24.673154 11154[11154] 0000000000000000 [SQL] 6646 SELECT * FROM SYS.ALL_VIEWS WHERE 1=0
2018-12-20T15:54:24.675714 11154[11154] 0000000000000000 [SQL] 6646 EXEC 0.0025660000
Last SQL statement executed by DB was:

0 0x00007f7f7a0a312c in waitpid () from /lib64/libpthread.so.0
1 0x00000000009fa5cb in dmExceptionManager::WalkStack(dmException*, int, siginfo*, void*) ()
2 0x00000000009fa988 in dmExceptionHandlerProc ()
3
4 0x00007f7f73d690e2 in __intel_ssse3_rep_memcpy () from /opt/oracle/product/client/lib/libclntsh.so
5 0x00007f7f73dc78c5 in kpuxcBindByNameRecord_dyncbk_fn () from /opt/oracle/product/client/lib/libclntsh.so
6 0x00007f7f73dca59d in kpuxcEntryCallback () from /opt/oracle/product/client/lib/libclntsh.so
7 0x00007f7f73f58e68 in kpuEntryCallback () from /opt/oracle/product/client/lib/libclntsh.so
8 0x00007f7f7318154f in kpubndn () from /opt/oracle/product/client/lib/libclntsh.so
9 0x00007f7f73150fe0 in OCIBindByName () from /opt/oracle/product/client/lib/libclntsh.so
10 0x0000000000b960b5 in DBCursorImp::Exec(DBDataBase&, unsigned int, char*, int, DBBlobReader**, unsigned int) ()
11 0x0000000000b9db05 in DBTableImp::IsView() ()
12 0x0000000000ba00a1 in DBTableImp::LoadColInfo() ()
13 0x0000000000ba0dd8 in DBTableImp::SetUp(DBTable&) ()
14 0x0000000000ba7793 in DBTableImp::DBTableImp(DBTable&, DBDataBase*, DBUser const&, DBString const&, unsigned int) ()
15 0x0000000000b8e516 in DBTable::DBTable(DBDataBase&, DBString const&, unsigned int) ()
16 0x000000000053ff4e in dmStartUpDatabase(dmServerGlobalContext*, int) ()
17 0x000000000047f3b5 in dmRPCInit(char const*, char const*, int, char const*, dmServiceFailoverList&, dmObject&) ()
18 0x0000000000482598 in dmRPCMain(int, char const**, dmBool, dmBool) ()
19 0x0000000000483e6d in main ()Server exception handler: caught exception: Thu Dec 20 15:54:25 2018 Internal exception: Exception: 0 at (RPC Protected Failure)