Hi @Andrew Pepper ,
It is a benign warning, nothing to worry about, this does not mean that your application will not run.
Use Windows Media Player as an example. Run this command from the Visual Studio Command Prompt in a temporary directory:
And you'll see:
TlbImp : warning TI0000 : Type library importer encountered a property getter 'sessionPlaylistCount' on type 'WMPLib.IWMPNowPlayingHelperDispatch' without a valid return type. The importer will attempt to import this property as a method instead.
Type library imported to WMPLib.dll
Which decompiles the type library back to IDL. Select the text in the right pane and copy/paste it into a text editor. Locate "sessionPlaylistCount" and you'll see:
HRESULT sessionPlaylistCount([out] long* pVal);
When you compare it with other properties you'll see the mistake, they forgot the [retval] attribute.
It isn't a problem because Tlbimp.exe will simply make it a method instead of a property. You'd write get_sessionPlaylistCount(out count) to use the broken property. It is inconvenient because the syntax is awkward but not otherwise a problem.
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