# Minimum Visual C++ Redistributable version? Getting: Unable to load emulator DLL

**URL:** <https://erlangforums.com/t/minimum-visual-c-redistributable-version-getting-unable-to-load-emulator-dll/4369>\
**Category:** Questions / Help\
**Tags:** elixir, windows, erlang-otp\
**Created:** [January 9, 2025, 1:19pm UTC](https://erlangforums.com/t/minimum-visual-c-redistributable-version-getting-unable-to-load-emulator-dll/4369 "2025-01-09T13:19:27Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![gilbertbw](https://erlangforums.com/user_avatar/erlangforums.com/gilbertbw/32/2723_2.png) [@gilbertbw](https://erlangforums.com/u/gilbertbw)\
**Post date:** [January 9, 2025, 1:19pm UTC](https://erlangforums.com/t/minimum-visual-c-redistributable-version-getting-unable-to-load-emulator-dll/4369/1 "2025-01-09T13:19:27Z")

</div>

Hello, I have been making mix releases of an elixir project, to run on windows.

These releases worked on my colleagues machines, but when running on a fresh VM I was getting this error:

```erlang
Unable to load emulator DLL
([...erts folder]\bin\beam.smp.dll)

```

I figured out this was because I did not have the Visual C++ Runtime installed. I am looking to make sure the minimum version of the Visual C++ Runtime is already installed, and if not install it, in the installer I am writing for this project. I am struggling to figure out what the minimum supported version of the runtime would be.

From [the install.txt file](https://github.com/erlang/otp/blob/53ffb6a1363180ec67c36e3baa9745ee73e7b5a3/erts/etc/win32/INSTALL.txt#L6) I see a redistributable is needed. I downloaded the [Erlang/OTP 27.2 Windows Zip Archive](https://github.com/erlang/otp/releases/download/OTP-27.2/otp_win64_27.2.zip) and see it includes the latest VC++ Runtime (14.42.34433.0), but I believe this is because the [Windows Upload GitHub action](https://github.com/erlang/otp/blob/926afc252f5a04bd4b6c4f37786c2b68d3453829/.github/workflows/upload-windows-zip.yaml#L51-L66) downloads the latest copy of vc\_redist for each release.

I also see that the [build GitHub Action](https://github.com/erlang/otp/blob/926afc252f5a04bd4b6c4f37786c2b68d3453829/.github/workflows/main.yaml#L287) uses windows-server-2022 builder, which also includes the latest Microsoft Visual C++ 2022 Runtimes (14.42.34433).

On my computer “C:\Windows\System32\mfc140.dll” is at version 14.28.29334.0, so I suspect that practically the latest version is not needed.

---

<div class="post-metadata">

**Author:** ![gilbertbw](https://erlangforums.com/user_avatar/erlangforums.com/gilbertbw/32/2723_2.png) [@gilbertbw](https://erlangforums.com/u/gilbertbw)\
**Post date:** [January 10, 2025, 5:08pm UTC](https://erlangforums.com/t/minimum-visual-c-redistributable-version-getting-unable-to-load-emulator-dll/4369/2 "2025-01-10T17:08:12Z")

</div>

I see that the latest Erlang x86 installer, for 27.2, installs version 14.29.30153 of the redistributable so I am going to assume that is the minimum version required.

* * *

n.b. I called this the Visual C++ Runtime above, I should have said Visual C++ Redistributable