When I first started using gretl last autumn I had an issue that one day I could no more open the session file of a project I had been working on over the course of several days. Now, with version 1.6.5 (Windows), exactly the same has happened again, and when I look through the files in the Documents and Settings folder as well as the one where I saved the session file, only the latter has actually been saved when I last did so, but the supporting files in the Documents and Settings folder are old and imcomplete, meaning that several save commands have failed?! The error message I am receiving when trying to open the session file is "Couldn't open session.xml" which is one of the files in the Documents and Settings folder, and which, as just said, has not been updated throughout several save requests. So tell me, what have I done wrong that this could happen? As much as I appreciate this free software, and even prefer to some of the lesser commercial packages for my particular purposes, I cannot afford to lose several days of work being in a commercial environment. Thanks for any assistance provided.