Windows 10
A Microsoft operating system that runs on personal computers and tablets.
10,618 questions
Windows 10 try to load non-existing mun files
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Ilona Kocur
16
Reputation points
I have a problem with time-consuming network Windows operations. When I load my *.dll resorces, Windows 10 is trying to load matching *.dll.mun files (it's not from my software, it's system specific) for all the dll's loaded in my program, from non existing folder SystemResources. Windows expects SystemResources folder to be located next to folder which contains my software. When dll's are on network share this causes access to IPC$ share, on some systems it's very time-consuming, which is very problematic.
Problem is visible in simple, clean mfc application. Below is trase from procmon, where it's visible that system is trying to access IPC$ share multiple times, where searching for mun files in SystemResources folder, which does not exist.
Windows 10
C++
C++
A high-level, general-purpose programming language, created as an extension of the C programming language, that has object-oriented, generic, and functional features in addition to facilities for low-level memory manipulation.
3,527 questions
{count} votes
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Jeanine Zhang-MSFT 9,181 Reputation points Microsoft Vendor2021-02-24T05:52:11.53+00:00 In earlier Windows builds, icon resource files were embedded in some DLL in the directory
C:\Windows\System32.Since Windows 10 version 1903, they have been relocated to:
C:\Windows\SystemResources.There is now a new extension for these files .mun instead of .mui
Could you please tell us, which version of win10 are you using ? If you are using an earlier version of Windows, I suggest you try to update the system.
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Ilona Kocur 16 Reputation points
2021-02-24T11:57:20.533+00:00 I do understand that new Windows 10 is loading mun files for system dll's from C:\Windows\SystemResources, this is fine. But why system is trying to load those files for my dll's files? Why it's looking for SystemResources folder next to folder with executable?, it this case \localhost\SystemResources.
My version of Windows 10: 20H2Is there any way to block this behavior?
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Jeanine Zhang-MSFT 9,181 Reputation points Microsoft Vendor
2021-02-25T02:19:28.77+00:00 Could you please provide some steps and a code sample that help us reproduce the issue? I try to run an MFC application, couldn't reproduce the issue.
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Ilona Kocur 16 Reputation points
2021-02-25T13:07:52.617+00:00 Steps:
- In Visual Studio create a new project->MFC App, with default properties:
- Build project as release x64.
- Start procmon, in "Process Monitor Filter" add process name filter with name of earlier built exe application from step 2:
- Enable network sharing for folder in which is exe file, in this case release folder, name it Test.
- Run from \localhost\Test exe file.
- In procmon you will see an attempt to access to \localhost\SystemResources\MFCApplication5.exe.mun
- In Visual Studio create a new project->MFC App, with default properties:
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Ilona Kocur 16 Reputation points
2021-02-25T13:08:11.73+00:00 Problems:
- Access to non-existing mun file for my exe file (the same is for dll's)
- Access to non-existing share \localhost\SystemResources
- On some systems with many dll's, which have slow access to network share (creating IPC$ share is time-consuming), is very problematic, and duration to start application from network is very long.
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Ilona Kocur 16 Reputation points
2021-03-31T09:48:33.09+00:00 Any updates for this problem?
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