It appears that there is a silent save failure for siml documents. If there is a typo in the siml it appears that the document will fail to save and "revert" to previous state. Since this is a silent error, a significant loss of work can happen. If there is an error saving the siml, the app should alert the user to the error and allow them to fix it and attempt to resave. I saw this error occur several times without understanding it so I fully believe it is reproducible.