Could not locate OCI dll Error

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.



  1. Eric
      October 7, 2009

    can you post the image or list what files you copied. The image is not showing. Thanks!

  2. Charlie
      November 4, 2009

    I’ve got the same problem, but I can’t see your screen shot. Could you email it to me?

  3. Marco
      November 25, 2009

    Same problem here.
    I have no files in my ORAHOME folder, only subfolders. So I don’t know what to copy. Can you please publish the screenshot or mail it to me?

  4. kwatog
      December 2, 2009

    sorry guys,! I have updated the post to include the screenshot.

  5. Frank Quednau
      December 14, 2009

    That’s indeed the answer. Which is kinda horrible. I have some simple Oracle client for 11g installed which already has a bin directory…alas, it contains stuff related to mts etc. What a mess…

  6. Bhageerath
      January 20, 2010

    Thanks man.Its working.

  7. Ravi Bhatt
      August 11, 2010


    I encountered the same issue with Oracle 11g when I was trying to login using PL/SQL Developer.

    I came across some steps which are worth sharing. And its clean means no ddl copying is involved.


    1) Login to PL/SQL Developer
    2) Go to Tools
    3) Click Preferences
    4) Click Connection in preferences pop-up
    5) Select “Orahome90″ under Oracle Home dropdown
    6) Apply the changes
    7)Close the PL/SQL shell
    8) Login again to PL/SQL Developer

    And the error is no more.

    Hope this post is worth to all the people encountering the same problem.

    Ravi Bhatt.

    • Muthu
        March 25, 2011

      Dear Ravi,

      I saw your response for this post. i am also facing the same problem.But i am using oracle 10g. PLSQLDeveloper version is 5.0.3 . in the prefernece menu of tools menu oraclehome doesn’t display any oracle home details.It’s EMPTY. But i can connect TOAD using my oracle 10g. it works fine. PLSQL dev not referring oracle TNS names.

      Could u pls provide solution for this ?


    • Beulah wilson
        May 9, 2012

      Thank you Ravi :)….Your post was indeed very worth and useful to solve the prob :)

  8. kwatog
      August 11, 2010

    Thanks Ravi Bhatt! The steps you provided works!

  9. Thameera
      August 30, 2010

    Thanx a lot it works :)

  10. Alex
      November 10, 2010

    Thank you

  11. Divya
      December 9, 2010

    Thanks a lot.!!!!!!!
    Its working…..

  12. PACE
      November 22, 2011

    Thanks, had this same problem after a fresh Windows install with 11g – working again

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