ARIS can not open the versions of the models

Good day!      Please help to find out why not open versions of the models.  Here is the situation: I have a database of models of organizational structure, created in ARIS 7.2.4. For all models prior to the changes created version. Recently found that the ARIS can not open some versions of the models. The program is very long, "thinks", almost - hangs. However, it occupies the entire free memory system, and at 100% load HDD. I checked in Task Manager: the full system memory used by an application "dbsrv10.exe"    Some small model in the end still open. But the version of the larger model - ever. I just have to restart the computer, as it does not respond.    Please help solve the problem. Maybe somehow restore the versioning? Thank you!    P.S. Please forgive me for my bad English.