When configuring OBS Studio actions, you may see a message that "Elgato Remote Control plugin is missing". That is the current name of the plugin that interfaces with OBS Studio. This plugin is installed into OBS Studio when the Stream Deck software is installed. This message appears if the plugin is not correctly installed or not able to communicate with the Stream Deck software.
In this case, please check the installation location for the Stream Deck software and OBS. If they are installed on 2 different drives or partitions for example (Drive:C and Drive D:, or both on any other Drive than the C: Drive - which is usually where Windows 10 is installed), then this may already be a reason for this problem.
In this case, please uninstall OBS and the Stream Deck Software.
1) Install OBS Studio onto the default Drive C:
https://obsproject.com/download
2) Install Elgato Stream Deck onto the default Drive C:
https://www.elgato.com/en/gaming/downloads
3) Reboot Windows 10 and retest it
For macOS, please make sure that OBS and the Stream Deck software both are installed and listed in Finder > Applications
If the issue remains, please contact our Support Team here.