This is a general error which indicates that the Process could not be run on the specified Runtime Resource for a particular reason. You may also encounter this error when loading up a new Blue Prism license file.
The cause of this error is revealed in the text labelled <REASON> in the error message. The run mode is not the primary cause. A run mode could not be set against the Process because of the specified reason, and therefore the Process cannot be initiated at this time until the resolution is identified.
One common reason is when the Runtime Resource has lost its connection to the Application Server due to a network connection issue. As a result, when the Runtime Resource automatically reconnects it will restart using a default licensing condition. This may prevent subsequent Processes from running on the resource.
How to resolve your issue
Resolutions to this issue are entirely dependent upon the individual causes presented in the <REASON> section of the error message.
For example, If the error message contains the following reason:
"Object Blueprism.Automate.clsCredentialsActions does not exist."
then a restart of the Runtime Resource will restore the correct licensing information and allow for Processes to be run.