The openclient is not open enough. The .Net proxies to PASOE can only be used from within a .Net Framework assembly.
Please allow them to be fully compatible with .Net Standard so they can be included in assemblies that run on either the .Net Core or the .Net Framework. Even WinForms and WPF are going to be running on .Net Core soon, so I don't see why the "openclient" is not able to do so.
(As an intermediate measure, please continue targeting the .Net Framework but simply remove any references to unnecessary API's which aren't available in the .Net Standard 2.0. Why do you have references in there to OleDb ??? )
Here is a link to the allowable API's in .Net Standard 2.0. It is very rich, although it doesn't include OleDb.
Here are more details about the need for an openclient that is more open: https://community.progress.com/community_groups/openedge_development/f/19/t/56089
Please consider doing this work in version 11.7.x. It will be a long time before some of us are ready for OE 12. (For example, some of us have to first migrate away from the HP-UX platform which is being retired.)
The ability to run a .NET core application that can communicate via the .NET proxies would be very helpful for us. It is currently limiting the platforms that we can deploy on, and the configurations in which we can deploy.
It appears that .net core 3 (preview 7) is a release candidate. It now includes the class OleDbException (for better or worse). So the old-school .Net framework proxies that are created from "proxygen" (11.7) can now be referenced in a .net core 3 application. It just works!
Aside from just adding those proxy-related assemblies into a core app, I also had to include a package reference to "Microsoft.Windows.Compatibility".
OpenClient works on the official release of .net core 3.
We don't even need Microsoft.Windows.Compatibility.
I suppose this is one idea that Progress can cross of their list for now.