Can the .NET API (Root/Application/CreateDatabaseForFile) be called from a standalone external WinForms application, or is it only supported as an Add-In running inside Manifold?

Yes, sure.

Thanks rk. I have a correct install at C:\Program Files\Manifold\v9.0 (Build 182). Root initializes fine with new Root(path-to-Ext.dll), but root.Application throws 'Invalid API operation'. Running .NET 6, x64, ExtNet.dll referenced from the same folder. What am I missing?

rk. Figured this one out. Please consider this problem solved.

NB! I have problem with the latest build (9.0.182.2) and standalone external .NET program.

I have reported it.

Attachments:
invalid_api_operation.png
runs_fine.png

Have you checked that exact same code against 9.0.182.1 or 9.0.182? Whether or not it can be reproduced with those, send it in as a bug report.

Yes, 9.0.182.1 and 9.0.179 are fine.

179 needs [STATread], 182.1 not, otherwise both work as expected.

There's a new build out, 9.0.182.3, which fixes that problem, and also adds a few nice features brought forward from the planned 26 July build. Thanks for reporting it!

The announcement: https://georeference.org/forum/t165559.0#165560