VBA Runtime error '-2147221164 (80040154)': class not Registered

Question

I developed a class library in Visual Studio 2019 using the .NET framework. Before building the project, I registered the.dll file to interop COM, and this process gave me a .tlb file. This class library was developed in VB.NET, besides that, it has a simple code: one class with one function (class calcular, function Soma):

It was possible to include the .tlb file in the reference of VBA and I develop a code in this language that uses the class of VB.NET to build the action of the button:

On the other hand, when I execute the code in VBA Excel it shows this message:

If a press the button debug "Depurar" VBA mark the line of the instance of the class

I read other questions about this error but there isn't a way to solve it without change my machine?

I already made a repair in my MS Office getting to uninstall to install again, can you help me to solve this error that prevents a run of my library in Excel VBA?

Did you make sure the bitness of your library matches the bitness of your Office installation? — GSerg, Feb 24 '21 at 19:26
Don't do all the registration and TLB generation stuff by hand... Visual Studio can do all of that for you — StayOnTarget, Feb 24 '21 at 20:55

Smith · Answer 1 · 2021-02-25T09:51:34.820

1

.NET COM visible dlls should be registered using regasm utility with /codebase option.

Assembly Registration Tool

edited Feb 25 '21 at 09:51

answered Feb 25 '21 at 07:45

Smith

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It works! I Tank you Very Much, Smith. Is important to remember that the (.dll) file needs a simple path and the command used: RegAsm.exe C:\path\file.dll. – DeSanterra Feb 25 '21 at 20:39
Glad I could help Leonardo. – Smith Feb 25 '21 at 20:54

score -1 · Answer 2 · answered Feb 24 '21 at 21:50

You must register the DLL before it can be used. Every time you compile a new version you need to run:

regsvr32.exe "fullPathAndFileName.dll"

You can add a post-build event to the Release in Visual Studio so that it registers the DLL every time you make a new release. If you are distributing this for others then you will need an installer that puts the DLL in to a proper location and then registers it.

You can unregister it by adding the /u flag

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VBA Runtime error '-2147221164 (80040154)': class not Registered

2 Answers2