SSACommonDllInit failed for enu(SBL-GEN-02505) is an error which I got while opening Siebel tools. Let's look into the issue, it is an Initialization error for the ENU (English) Client. So it can be either a configuration issue or a file missing issue.
You can try searching installation directory for the .cfg file. but there wont be a result...!!! How this could happen? The answer is simple. Installation got corrupt. Even if we copy files from a working environment the client wont function properly. And a common issue is internet explorer gets close automatically.
The best practice is to Re-Install Siebel thick client.
In case of configuration error try editing the "Target" in your shortcut as follows
C:\Siebel\8.1\Client_1\BIN\siebel.exe /c
C:\Siebel\8.1\Client_1\bin\enu\cs.cfg /u sadmin /p sadmin /s c:\spool.sql
Each part of the above line can be explained as
C:\Siebel\8.1\Client_1\BIN\siebel.exe > Path to siebel.exe
/c
C:\Siebel\8.1\Client_1\bin\enu\cs.cfg > Path to cfg file (Configuration)
/u sadmin /p sadmin >User name and password, This section is optional.
/s c:\spool.sql > Spooling, enable spooling to get the siebel generated queries, use this feature for debugging,This is also an optional parameter.