I have seen the below error a few times on client machines in the past few weeks. Usually one of the 2 steps below fix the issue
Instructions (Option 1)
Copy the missing .dll file to the Teams install location
- Open File Explorer
- Enable Hidden files (tick the box)
- Navigate to the following location and make a note of the username folder and version number folder (select the most recent version). We will need these for the step below
C:\Users\USERNAME\AppData\Local\Microsoft\Teams\current - Download the ffmpeg.dll file from the link below and store in the above location (remember to rename the file to ffmpeg.dll after downloading)
- Restart the machine and Teams should now load successfully
ffmpeg.dll (after downloading the file rename to removed the .download from the end of the file name)Download
Instructions (Option 2)
If the above steps dont work or you cant find the location Teams will need to be uninstalled and reinstalled
- Open the Control Panel
- Select Programs and Features (or Windows Key + R and type appwiz.cpl and press Ok)
- Select Microsoft Teams
- Click Uninstall
- Follow the prompts and select all default options to uninstall
- Click on the following link and click on Download for Desktop
https://www.microsoft.com/en-au/microsoft-365/microsoft-teams/download-app
- Run the downloaded file to install Teams and Teams will now run without error