Excel Add-In warnings
See the question and my original answer on StackOverflowThese errors are no big deal. It just means some types in the COM Type Library cannot be imported automatically. From Visual Studio build process (or MSBuild task, used in the backend), I don't think you can remove these errors. They are produced by the .NET internal Type Library Importer with no flags you can pass.
What you could do though is create the interop assemblies you need using the Tlbimp.exe (Type Library Importer) tool instead, prior to your other build actions, and reference them instead of letting the IDE to do the job. Latest versions of the tool understand a silence
switch.
Without the switch:
C:\Program Files (x86)\Microsoft SDKs\Windows\v8.0A\bin\NETFX 4.0 Tools\x64]tlbimp C:\Windows\system32\stdole32.tlb
Microsoft (R) .NET Framework Type Library to Assembly Converter 4.0.30319.17929
Copyright (C) Microsoft Corporation. All rights reserved.
TlbImp : warning TI3001 : Primary interop assembly 'stdole, Version=7.0.3300.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is already registered for type library 'C:\Windows\system32\stdole32.tlb'.
TlbImp : warning TI3002 : Importing a type library into a platform agnostic assembly. This can cause errors if the type library is not truly platform agnostic.
TlbImp : warning TI3016 : The type library importer could not convert the signature for the member 'stdole.DISPPARAMS.rgvarg'.
TlbImp : warning TI3016 : The type library importer could not convert the signature for the member 'stdole.DISPPARAMS.rgdispidNamedArgs'.
TlbImp : warning TI3015 : At least one of the arguments for 'stdole.IDispatch.GetIDsOfNames' cannot be marshaled by the runtime marshaler. Such arguments will therefore be passed as a pointer and may require unsafe code
to manipulate.
TlbImp : Type library imported to stdole.dll
With the silence switch (multiple occurrences):
C:\Program Files (x86)\Microsoft SDKs\Windows\v8.0A\bin\NETFX 4.0 Tools\x64]tlbimp C:\Windows\system32\stdole32.tlb /silence:3016 /silence:3015 /silence:3001 /silence:3002
Microsoft (R) .NET Framework Type Library to Assembly Converter 4.0.30319.17929
Copyright (C) Microsoft Corporation. All rights reserved.
TlbImp : Type library imported to stdole.dll