A Google search shows me the answer, provided by Terry Dykstra!

I have attempted to create a new DWO from scratch. The SQL is brain dead simple and I tested my user rights in SQL+ first, successfully.

But even a brand new dwo has the RETRIEVE button disabled.

Try creating a new grid datawindow, dummy up the SQL until you can convert to syntax, then paste in your select (and set up the arguments again).

If it works, save it as new, then compare the working/non-working datawindows. Everything up to the actual layout data (columns, titles) should be pretty much the same. That should give you some indication of what's causing issues.

If it doesn't work, that indicates something with the SQL that PB is having problems parsing, but not telling you about. You'll have to start tearing it apart one piece at a time till it works, then see what you can do to replace the offending bit.

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Just saw your revisions.

What happens if you create a new DW from scratch?

Well, it's been working with that database  - my primary development database - for two years.
Until today.

It's like a switch was thrown somewhere!!!!

 
OK, I've tried connecting to three different databases, and it the behavior is the same - it does not matter to which database I am connected, the RETRIEVE button is disabled.

Hi Olan;

  I am not sure if this has anything to do with your predicament ... but, O12C was not supported by PB until PB 12.6 - 1st EBF release.

Regards ... Chris