Attribute, block and font corruption

Our files seem to have become corrupted upon opening today. I checked saved .bak files and other .dwg files in our root folder and they all appear to have the same problem.

When I am in model space and zoom extents, I can see items spread out in 90 degree quadrants for hundreds of feet. When I examine the entities, some are text from blocks (and still part of the block), and some are plain text that has been changed to another weird text style that we never use (I don't know the name of it, but it has numbers and letters in the font style name). I also noticed attributes appear not to have text in them, but was able to modify them and change the text style back from the weird name to standard text to get them to read correctly. Typical note fonts are reading correctly in most instances, but larger fonts such as sheet titles are changed and sheet numbers in paper space have simply vanished.

I have tried restarting the program, recovering and repairing the drawings with no success. I am at a loss as to what caused this problem and how to remedy it without spending countless hours correcting each item of text one at a time. I don't know how to fix the blocks yet.

Any help would be appreciated! I am using AutoCAD 2015 LT. We have had this program working fine for over a month after upgrading from AutoCAD 2003 and getting new computers.

Perhaps it has something to do with the font that was used.

Attach a sample drawing to your next post. Someone here will take a look at it.

This appears to be a computer memory issue (perhaps lack of RAM). When we open on an upgraded machine the drawing opens fine. Thank you for you offer of assistance!

Thank you for stating that the problem was resolved and how