Error message
In the message, %s marks a value that the engine fills in when it raises the error.
The story
The engine could not start, and the message points at a file about dimensions. Here is the idea. Every being in rush has an identity, and that identity comes with six required dimension fields. Which dimensions exist is not hidden inside the code. It is written on disk, in dimensions.feml, so that there is exactly one place that says what an identity is. This time, the engine could not use that file. Maybe it could not read it, or maybe it read fine but declared no dimensions at all. Either way, the engine has no statement of what an identity should look like, so it has nothing to check itself against. Think of an inspector with no blueprint: anything he approves means nothing. The engine could fall back on a default baked into the code, but that would create a second source of truth, and the whole point of this design is to have only one. So it refuses to be born. The message tells you the file path and the reason it failed. Check that the file exists, can be read, and really declares its dimensions. Fix that, and the engine will start.
Text from the Rush engine's error catalogue.