{"id":11533,"date":"2011-02-10T07:00:00","date_gmt":"2011-02-10T07:00:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/oldnewthing\/2011\/02\/10\/psychic-debugging-because-of-course-when-something-doesnt-work-its-because-the-program-was-sabotaged-from-above\/"},"modified":"2011-02-10T07:00:00","modified_gmt":"2011-02-10T07:00:00","slug":"psychic-debugging-because-of-course-when-something-doesnt-work-its-because-the-program-was-sabotaged-from-above","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/oldnewthing\/20110210-00\/?p=11533","title":{"rendered":"Psychic debugging: Because of course when something doesn't work, it's because the program was sabotaged from above"},"content":{"rendered":"

\nWhen something stops working, you begin developing theories\nfor why it doesn’t work,\nand normally, you start with simple theories that involve\nthings close to you, and only after you exhaust those\npossibilities do you expand your scope.\nTypically, you don’t consider that there is\n\na global conspiracy against you<\/a>,\nor at least that’s not usually your first theory.\n<\/p>\n

\n

\nI’m trying to use the XYZ.DLL that comes with your product.\nI have successfully registered this DLL (as specified in the\ndocumentation) by performing a\nregsvr32 C:\\path\\to\\XYZ.DLL<\/code>.\n<\/p>\n

\nAccording to the documentation, I should now be able to create\na Xyz.Xyz­Widgetizer<\/code> object,\nbut when I try to do so from C#, I get the exception\n<\/p>\n

\nRetrieving the COM class factory for component with CLSID\n{...} failed due to the following error: 80040154.\n<\/pre>\n
\nI tried using the Visual Basic code sample which comes with\nthe documentation, which contains only two lines:\n<\/p>\n
\nDim oXyzWidgetizer\nSet oXyzWidgetizer = WScript.CreateObject(\"Xyz.XyzWidgetizer\")\n<\/pre>\n
\nHowever, it still fails with the following error:\n<\/p>\n
\nMicrosoft (R) Windows Script Host Version 5.7\nCopyright (C) Microsoft Corporation. All rights reserved.\nC:\\test.vbs(2, 1) WScript.CreateObject: Could not create object\n                  named \"Xyz.XyzWidgetizer\".\n<\/pre>\n
\nHas support for the XyzWidgetizer been silently dropped?\n<\/p>\n<\/blockquote>\n
\nLet’s look at the error message more closely.\nError 80040154 is REGDB_E_CLASSNOTREG<\/code>:\nThe class is not registered.\nTherefore, whatever regsvr32<\/code> did,\nit didn’t register the class.\n<\/p>\n
\nMy psychic powers tell me that you registered the 32-bit version of\nXYZ.DLL on a 64-bit machine.\n<\/p><\/blockquote>\n
\nRegistering the 32-bit DLL records the entries into the 32-bit registry\n(because\n\n32-bit programs run in an emulator<\/a>),\nand the 32-bit registry\nis not consulted when you try to create a COM object\nfrom a 64-bit application.\nLetting 64-bit applications see the registration for 32-bit DLLs\ndoesn’t actually accomplish anything because\n\nyou cannot load a 32-bit DLL into a 64-bit process and vice\nversa<\/a>—even if a 64-bit process can figure out what DLL it wants,\nit won’t able to load it.\n<\/p>\n
\nIt so happens that my psychic powers were correct.\nHow did I know that the person asking the question was running\nthe 32-bit version of XYZ on a 64-bit version of Windows?\nI didn’t, but it was the simplest theory that fit the (extremely\nlimited) data.\nAnd it didn’t involve a global conspiracy.<\/p>\n","protected":false},"excerpt":{"rendered":"
When something stops working, you begin developing theories for why it doesn’t work, and normally, you start with simple theories that involve things close to you, and only after you exhaust those possibilities do you expand your scope. Typically, you don’t consider that there is a global conspiracy against you, or at least that’s not […]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[26],"class_list":["post-11533","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-other"],"acf":[],"blog_post_summary":"
When something stops working, you begin developing theories for why it doesn’t work, and normally, you start with simple theories that involve things close to you, and only after you exhaust those possibilities do you expand your scope. Typically, you don’t consider that there is a global conspiracy against you, or at least that’s not […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/11533","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=11533"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/11533\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=11533"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=11533"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=11533"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}