If you are connected in P6 Professional and your machine goes into hibernation for > 1hr, the next operation you attempt will result in the “Internal error Invalid Session” error.
Based on your note below, this is likely due to exceeding the 1hr inactivity period (machine moving into hibernation for greater than one hour while you have a connected session).
If the layout you were using did not carry over to the new session, it was likely not updated in your USERDATA row which gets set upon successful logout of P6 Pro (which did not happen in the case below due to abnormal termination from inactivity).
