Blue Iris

Hey all,

Been running BI 4 on my Windows 10 computer.

Microsoft just installed the May 2019 update on my system and suddenly BI 4 stopped running giving the error that WMASF.DLL was missing.



I downloaded BI 5 and installed it and it says WMVCore.DLL is missing.



Neither version runs. I scanned the forums and tried installing the VC Runtime for 2015-2019 and that didn't fix the problem. Can anyone help with this?

In the past "WMVCore.DLL missing" or "WMVCore.DLL not found" meant you were running Windows 10 N edition and did not have Media Player and related technologies installed. The solution was to download and install the Media Feature Pack from Microsoft. Since this happened after the Windows feature update installed Windows 10 version 1903 (May 2019), I suspect the previous Media Feature Pack was removed.

If you have a Windows 10 N edition OS installed then go to https://www.microsoft.com/en-us/softwar ... eaturepack and download and install "Media Feature Pack - Version 1903 ( May 2019).

If you do not have a Windows 10 N edition OS, then open Control Panel -> Program Features -> Turn Windows features on or off and install Windows Media Player under Media Features.

If you manually installed Microsoft Visual C++ Redistributable for Visual Studio 2015, 2017 and 2019, make sure you installed the correct version for your PC's architecture. On Windows 10 64-bit OS, you should install vc_redist.x64.exe, whereas on a 32-bit OS, you should install vc_redist.x86.exe. Here is the link for anyone interested: https://support.microsoft.com/en-us/hel ... -downloads

This fixed my problem. You were correct that I was running Windows 10 Pro N. Thanks!

awesome... huge thanks.....

After updating my W10 Pro N today with the following updates, BI threw the "WMVCore.DLL missing" error at startup.
Feature update to Windows 10, version 2004
KB4601050: Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10, version 2004...

I tried to install "Media Feature Pack - Version 1903 ( May 2019)" but Windows says "The update is not applicable to your computer".

I realized that I should look for a Media Feature Pack for a 2004 or newer version of W10 and I found instructions to "navigate to Settings > Apps > Apps and Features > Optional Features > Add a Feature and find the Media Feature Pack in the list of available Optional Features." That fixed my issue.

I thought I'd leave this here for anyone else who searches the forum.