The document will be in RAM 8 hour by default, if you want to change this option you can do it at the QMC>System>server >Documents ans change in Document Timeout.
To be honest i don´t understand your problem. From the screen shot is look like you got a session timeout but you say you remake the application and is work? Well if you restart the service (QVS), can you access the document with out the remake action? IF yes, is could be related to an corrupt share file or meta data file.