This error will occur if the process developed on a newer version of Studio is being opened/executed on an older version.
Specifically, two scenarios are possible:
- You have created a project on Studio CE 2019.7 and you are trying to open it with 2019.6
- You have created a project on Studio CE 2019.7 and you are trying to run it via Orchestrator on a machine that has an older version of Studio CE/Robot installed.
In both cases, updating to the latest version 2019.7 on all machines you use is the advised fix