= Error Message: Dependent module ___ could not be loaded. The module has an invalid magic number. =

"Invalid magic number" errors indicate a "bitness" mismatch -- a 32-bit application trying to load a 64-bit library, or a 64-bit application trying to load a 32-bit library.

On Mac OS X and most Unix-like OS, you can check the bitness of any file with a simple command -- 
{{{
file /path/to/file
}}}

On 64-bit Windows, 32-bit components are generally installed within the {{{Programs (x86)}}} or (counterintuitively) the {{{SysWow64}}} directories.  64-bit components are generally installed within the {{{Programs}}} or (counterintuitively) the {{{System32}}} directories.

On a client host (whether Single-Tier or Multi-Tier), the bitness of the client application (e.g., HSODBC, DG4ODBC, Crystal Reports, Microsoft Excel) forces the bitness of the data access driver and/or driver manager.  On Single-Tier client hosts, the bitness of the client application also mandates the bitness of the DBMS client libraries (e.g., {{{libesql92.so}}}, {{{libifsql.so}}}).

On a Multi-Tier Broker host, the bitness of the DBMS client libraries (e.g., {{{libesql92.so}}}, {{{libifsql.so}}}) forces the bitness of the Request Broker and Database Agent.

If you have both 32-bit and 64-bit components present, this error can be resolved by ensuring that all executable and shared library path (e.g., {{{PATH}}}, {{{LD_LIBRARY_PATH}}}, {{{SHLIB_PATH}}}, {{{LIBPATH}}}) variables are set to target components of the same bitness.  

If you do not have both 32-bit and 64-bit components present, determine the bitness of the "controlling" components, and acquire and/or install the other components to match.