Even when we set the dll file and/or user data folder, this error is thrown. Because we focused more on the macOS app, we did not actively work on the Windows app for 3 month. But mid of December it was working. Even when we change the JUCE version back to 6.1.2 we used then, the error is still thrown.
So the WebView2Loader.dll is not enough with an already installed Edge… But it was working… Strange I did not uninstall or changed my windows since then… only updated JUCE from 6.1.3 to 6.1.6.
Weirdly, WebView2Loader.dll works fine for me with my VST3 when using Cakewalk x64, but not when using Reaper x64 (in the latter case, it defaults to the IE display mode …).