I have a model created with Open Studio, version 1.5.0. I import this model in 1.5.1 and it was still running, but upgrading on the beta 1.5.2 version, Open Studio won't load DDY file (after I select the DDY, it disappear when I shift to another tab). Now the problem is I have a newer .osm model , and only the older version of the program working. I try to uninstall and reinstall. I try to edit the .osm change the version tag form 1.5.2. to 1.4.0, without results. I know that I was really foolish to run my .osm with a testing version, but ...that has happened , and that file costs a week of work. Please help ! Cesare