If you are using 10g client with PL/SQL developer, you may encounter the message “Initialization error: Could not locate OCI dll” when launching PL/SQL Developer. It does not happen with the 8i client so I already suspected that it must be with the 10g client that I recently installed. Luckily, I found this thread in Oracle OTN forum and the solution seems to be easy.
All I have to do is copy a whole bunch of files from the ORAHOME folder to ORAHOMEbin. It seems like PL/SQL Developer is hardwired to find the files under the bin folder. It did the trick and my sql editor is now working. I hope it fixes yours too.
Here’s the screenshot of the files I copied. Take note that I copied them instead of just moving so as not to break anything.