This error appears for Consolidation job. It means that the mentioned source agents are configured to consolidate the files into one destination folder. Consolidation job is designed in a way that all source agents are uploading their files into their own designated subfolder on destination server and do not exchange data with each other. This is achieved by using %SRC:AGENT_NAME% tag in destination path. If this tag is removed from path, the error pops up.
How to resolve this issue?
To fix it go to edit the job, at step "Destination agents' add %SRC:AGENT_NAME% tag into the path so that looks like this:
C:\Users\Public\Documents\Resilio Connect Agent\Consolidation Job\
Surely, you can have your preferred location instead of C:\Users\Public\Documents\Resilio Connect Agent\Consolidation Job\