We are currently planning an server migration. We have our current server on SDE 10.1 on Oracle 11 Currently our editors are on ArcGIS 10.1 with Oracle client 11.2

Our new server is setup and ready for testing. It is at SDE 10.3.1 on Oracle 12c. However when ArcGIS Desktop existing clients try to connect to it they are getting an error:

Failed to connect to database. Underlying DBMS error [unknown Error No extended error]


I had thought that newer versions of SDE were backwards compatible with older ArcGIS desktop clients. Is there a connection setting that has to change? The connection settings we are using work fine with ArcGIS desktop 10.3.1 :

Connection we are trying to use

  • 1
    You have the directionality wrong -- Newer CLIENTS can usually connect to older SERVERS, not old clients to new servers. ArcGIS 10.1 was released long, long before Oracle 12c was released, and does not support 12c. You should always upgrade client nodes first, then the servers.
    – Vince
    Aug 24, 2015 at 22:59
  • @Vince I think that link you sent me is for SDE support for Oracle, not client support. I know I've seen it documented that ArcGIS Desktop versions support new SDE databases. Let me see if I can dig it up.
    – Dowlers
    Aug 24, 2015 at 23:15
  • Oh and we are planning on upgrading the clients to 10.3.1 at the same time. thankfully, I'm just hoping to have the editors test one or two things first. I'd upgrade them first but we ran into a strange bug with ArcObjects spatial queries giving wrong results.
    – Dowlers
    Aug 24, 2015 at 23:20
  • @Vince OK I think I figured it out. From this: desktop.arcgis.com/en/desktop/latest/manage-data/gdbs-in-oracle/… it looks like 10.1 client only support SDE 10.3.1 on Oracle 10 or 11. Thanks for your help as always
    – Dowlers
    Aug 24, 2015 at 23:36

2 Answers 2


According to this compatibility document ArcGIS 10.1 can connect to Oracle SDE 10.3.1 only if it is oracle 10 or 11.

The underlying DBMS must be Oracle 10g or 11g. See the ArcGIS 10.1 system requirements for supported versions.

  • The "ArcGIS 10.1 system requirements for supported versions" is the link I provided.
    – Vince
    Aug 25, 2015 at 1:04
  • I think I got confused by the system requirements document. I read it as database requirements for SDE 10.1, not for ArcGIS desktop client support. I always thought ArcGIS desktop desktop client support was controlled by the RDBMS client.
    – Dowlers
    Aug 25, 2015 at 16:45
  • Direct Connect is a server capability, run on the client. Server requirements dictate Direct Connect compatibility. Forward compatibility is only working here because there have been no significant changes to the server.
    – Vince
    Aug 25, 2015 at 16:56

Here are few web-links which might be helpful:



  • 1
    Please refrain from only using links in your answer--those go stale quickly. Give a description on what to do to solve the problem.
    – MaryBeth
    Jun 23, 2016 at 20:34
  • Yes. First link is dead, 2nd link is irrelevant Oct 18, 2017 at 23:36

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