Try pulling up the Task Manager(Control +Alt +Delete), go to the Processes tab, click on Bryce.exe, then right click and choose Set Priority and choose Above normal or High, you will get a dialog box asking if you are sure you want to do this, click yes, then try saving the file. Try "Above normal" setting first,................it is important not to have any other apps open or running when you do this as your machine may freeze.  I have used this method with good results most of the time. If the file saves properly, close the Task Manager when you are finished (this will reset the priority to normal). Hope this works. As I said, it has worked for me. Oh yeah,.....do not minimize the Task Manager, this will reset the priority to Normal. Instead, on the Task Manager go to the Options pull down at the top and uncheck "Always on top" before you start this process.

"Any club that would have me as a member is probably not worth joining" -Groucho Marx