I received an error "Inkscape encountered an internal error and will now close" and didn't think anything of it, but then it happened again later, and also while I was out of the room my computer restarted to install updates.

Now two of the .svg files that I had open aren't working. The first gives me the error "Failed to load the requested file" and when I open it in Chrome I get the error:
"error on line 1 at column 1: Document is empty"
If the document is empty, I don't know why it is still 26.5 MB

The second file opens in Inkscape but appears empty. When I open it in Chrome I get the error:
"error on line 9519 at column 20627032: Char 0x0 out of allowed range"
This document is 31.6 MB.

Is there any way to recover anything from either of these files?!

Welcome aboard!

The file size is promising however had seen people posting damaged svg-s here filled up with only nul characters -not even sure how they achieved that.
By a sudden error when saving -running out of resources usually- the bottom part of the code is chopped off.
Your document should have a similar structure to this.
If parts are missing -end tags for example- you can edit them back manually in a notepad.
From that matter the second error message seems more promising.

Share the damaged files, so we can look at them and try to fix.

https://www.dropbox.com/s/qnl902co3pj1u ... l.svg?dl=0
https://www.dropbox.com/s/l63c0rrw3o521 ... d.svg?dl=0
These are the two links from Dropbox to the two files. Hopefully they aren't completely tarnished

Hmm bad news.

Not a single line can be recovered from the first one, all it contains is nul characters. (Strangely that character is not supposed to be in svg-s either, it's more likely in pdf-s.)

The second one has 9519 lines of code intact -however that's chopped almost right after the metadata part.
It shows the first object was supposed to be a raster image but the rest is missing.
There may be some information that can be used from it, although even notepad++ is struggling with the editing.
Trying to delete the bottom line of an embedded raster image and adding the end tags.

To prevent such a loss in the future, be sure to activate autosave (Edit -> Preferences -> Input/Output -> Autosave). Btw. there's a newer Inkscape version available that fixes a couple of bugs of the version you are using atm.

I have already discovered the autosave feature (too late obviously), but I didn't know about the newer version of Inkscape, thank you @Moini

@Lazur I didn't have much hope for the first file I attempted to open the second file in Notepad++ but I don't know code and didn't know what I was looking for, and my program ran very slowly and was not responding, so I stopped trying to look at the code.

Don't you have earlier version of these files, so that you don't have to start all over? Or had they grown so large within the first session, before they were saved?

This might be slightly off topic. I wonder if Inkscape should be able save and close a file in case of unexpected shutdown? It seems like I've had crashes, and was surprised that the content I had just been working on was saved. Maybe shutdown is different from a program crash, but I wonder if it would be hard to make Inkscape able to recognize when the computer is about to shut down? (Note - I ask that not being a programmer or developer. An innocent question.)

Btw, must be Windows 10, if it went to get updates without warning, shut down, and locked you out.

This is as far as I could you with the first file: https://www.dropbox.com/s/1zq3evp43kz2p0f/Spinnerets_board_bigmat_horizontal_f.svg?dl=1

We're missing all but the fist 136 lines of the woodgrain texture and possible anything else that was after that... so no good at all, but I had fun trying to recover it so whyt not share it?

Couldn't download the second one.

Hello.

New to the forum, but long time user of Inkscape. I've got the same problem with a crash during a save, a "Failed to Load..." message, 0 line in Notepad and showing 0 file size. I lost 4 days of work. I don't want to go to a different app, but this is a huge lose.

My question is this being worked on by the community and how can I best prevent this from happening in the future?

Thanks

Maybe you need to enable the autosave feature, so that you'll always have a backup? Inkscape Preferences > Input/Output > Autosave

And the other thing I would do, is be mindful of your file size. It depends on how much RAM you have on your computer. But the op here had a file larger than 26 mb. We don't know how large it was, but 26 mb is what was not lost. And that's a pretty big file!

Personally, I don't like to have SVG files larger than approx 20 to 25 mb. Mostly because they have performance issues in Inkscape, but also because my computer doesn't like to handle them.

Additionally, make sure to always update to the latest stable version. Are you using 0.92.3? (Tomorrow, we'll release 0.92.4, so you may also wait for that)