This is NOT the known bug with 0.48.2 where there is no Save As dialog. This is version 0.48.1, and when I use either File menu > Save As or Save, the dialog appears very briefly (less than 1 second) before the whole thing closes down! This certainly has never happened before. I've restarted my computer a couple of times, but it keeps happening.
I did get a Windows Update yesterday, which was for Windows Defender. Could the new Defender def be recognizing some normal Inkscape saving process? Note that I have very little technical knowledge. It's just that that update yesterday is the only change to my computer since the last time Inkscape was working properly. I think I'll be able to find something in the Events Viewer, if this is related to Defender (although I'm not positive). So I'll look for that while waiting for replies.
Gosh, I hope we can figure this out soon! What will I do without my Inkscape??


Thanks for your help

Edit
I haven't found anything in Event Viewer at the same date/time as the Inkscape crashes. Although there are TONS of logs in Win7 as compared to WinXP, and I can't possibly look at all of them. If anyone can point me in the right direction? I did find a Windows Defender log, but it's empty.
I've also checked the Defender program. I've added Inkscape so that it's excluded in scans, but I can't figure out how to exclude it from real-time protection (which must be what's happening, if Defender is the culprit). But note that I'm not getting any kind of alert or notification, and still don't know if this is related to Defender. It could be something else entirely, for all I know.
I have no idea what's happening! I just know that I want my Inkscape back.
I have one more thing to try though. So far, this has been happening when trying to save files for the first time (File menu > Save As or Save, or Ctrl +s). Next I'm going to try opening a file that's already existing, to see if I can save changes. Will report

Edit #2
Ok, the next thing I tried was to open an existing file. Just to be safe, I thought I'd save a copy of the file, so I wouldn't lose it. But the same thing happened when I did File menu > Save a Copy. The dialog came up for just a fraction of a second before both the dialog and canvas went away (crash). So then I scrounged around and found a file that I wouldn't mind losing. It turns out that I CAN save new changes without any apparent problems (File menu > Save, as well as Save As!). So yay, at least I can still work on exising images, until this gets fixed. But this still is a serious problem that I really would like to fix.
Let me summarize: New and not previously existing files -- Save As, Save, Ctrl + s and Save a Copy all cause crash. For existing files, Save As, Save, Ctrl + s and Save a Copy, all work as expected.
I'll do some more research on Defender, since yesterday's update is still my only clue, and I'll keep topic updated.