Avformat-59.dll -

In previous years, you might have seen avformat-58.dll or avformat-57.dll . As the FFmpeg developers improve the library and change the application programming interface (API), the version number changes to ensure software knows which generation of the library it is interacting with.

Unlike Windows system DLLs, avformat-59.dll is part of a clean Windows installation. It is installed by third-party applications. Here are the most common reasons for errors: avformat-59.dll

There are several reasons this happens:

Since FFmpeg depends on these, a missing or broken VC++ runtime can cause avformat-59.dll errors. In previous years, you might have seen avformat-58

If the error occurs in a suite of tools (like the Adobe Creative Cloud), ensure the suite is updated. Software developers frequently patch compatibility issues in updates, and an update might restore the missing avformat-59.dll or update the software to use a newer library entirely. It is installed by third-party applications

C:\Program Files\FFmpeg For Audacity\ or within the installation folder of OBS/Tenacity.