I had faced some upgrade issues and please find the issue and the resolution to the fixes.
1. Error occurred loading library libclntsh in informatica admin console
Reason: The Informatica Repository is finding for this particular library file which is present after the installation of Infomatica. This is present in Informatica library path and not the Oracle Client.
Resolution: Add to the LD_LIBRARY_PATH the Informatica library path.
Note: Please refer the link below to set the LD_LIBRARY_PATH
2. The backup file
C:\Informatica\PowerCenter8.6.1\server\infa_shared\Backup\Oracle_BI_DW_Base.rep’s code page (UTF-8 encoding of Unicode) is not one-way compatible to repository Oracle_BI_DW_Base’s code page (MS Windows Latin 1 (ANSI), superset of Latin1).
Unable to restore Repository.
Reason: The code page set up in the Linux box is Unicode while our database where the repository content is present is in MS Windows Latin 1.
Resolution : Please set the LANG_ALL and LANG=C in the Environmental Variables location and restart the box or source the profile and this issue will be resolved.
Note: Please refer the link below to set the Language Variable
Reason: This issue will occur only if the upgradation is to be taken place in completely new environment. In the repository schema the hostname is referring to the old box while the new host name is a different name.
Resolution : Change the hostname to the currnent Informatica 9.1 box in the OPB_REP in the informatica schema in the database
Note: Please refer the link below to set the host name in the Informatica Schema
Other useful links you might be interested.