I have been working on a Windows 10 for a week as my mac no longer works well. For some reason, a few of my aic files will no longer open after I worked on them for several hours. I had a file that was large and starting to take quite a while to save so I wanted to do do a "save as" with it and make two smaller files instead of one large one. I deleted some items from the new file and wanted to open the original file, but it would not open. I closed the new file and tried to open the old file then, and it still wouldn't. Now, I cannot open either file. All I get is an error message. I tried restarting Illustrator. I tried restarting my computer. Neither of these things helped. I tried seeing if there are any viruses on my computer. I also checked to make sure I have plenty of space with storage on my pc as well. No viruses and plenty of storage (31GB of Ram usale and 151 GB of space available on my local disk). Here are the links to the files, if someone from the Adobe Support Community could take a look, I would really appreciate it!!