This problem can usually be resolved by editing the RS_SQLIF.INI file as follows:
[Oracle]
;LD=ORAWE850
ORACLEDLL=c:\oracle\bin\ociw32.dll
SynonymSupport=1
QualifySynonymsWithOwners=0
HasOwners=1
SQLHasOwners=0
SQLHasDatabases=0
Make sure that the OracleDLL setting has the correct path. Depending
on how Oracle was installed, you may need to change this setting.
The default location of the RS_SQLIF.INI file is in the C:\Windows directory.