From time to time I blog about strange cases of errors when loading add-ins for Visual Studio. At least three of them have been about errors with hexadecimal codes such as 8013XXXX:

The strange case of <Unknown Error> 8013150A loading a Visual Studio add-in
https://www.visualstudioextensibility.com/2009/03/24/the-strange-case-of-lt-unknown-error-gt-8013150a-loading-a-visual-studio-add-in

The strange case of <Unknown Error> 8013141A loading a Visual Studio add-in
https://www.visualstudioextensibility.com/2008/11/28/the-strange-case-of-lt-unknown-error-gt-8013141a-loading-a-visual-studio-add-in

The strange case of error 80131018 loading a Visual Studio add-in
https://www.visualstudioextensibility.com/2007/03/23/the-strange-case-of-error-80131018-loading-a-visual-studio-add-in

When those errors happen, the description that Visual Studio shows is “Unknown Error”. I’m sure that Visual Studio could do a better job getting the description of such errors, but meantime you have to Google them, which usually gets no much meaningful information. If you ever encounter such error that you don’t get much information about, here is what you can do:

1) Those errors are coded in the corerror.h file. You have an online copy of that file at the Koders web site www.koders.com: enter “file:corerror.h” (without quotes) as your search term to get the file.

2) You will notice that the file contains a lot of error definitions such as EMAKEHR(0x101A)

3) So, you really need to search for the last 4 hexadecimal digits of your error. For example for the error 8013141A you would get:

#define CORSEC_E_INVALID_STRONGNAME     EMAKEHR(0x141a)         // Strong name validation failed

and then you know that the error is related to an invalid strong name.

If you are curious, the EMAKEHR macro is defined as:

#define FACILITY_URT            0x13
#endif
#ifndef EMAKEHR
#define SMAKEHR(val)            MAKE_HRESULT(SEVERITY_SUCCESS, FACILITY_URT, val)
#define EMAKEHR(val)            MAKE_HRESULT(SEVERITY_ERROR, FACILITY_URT, val)

So you now know where the 0x13 digits (3th and 4th) of all those errors come from.

Hope this helps.