File saved yesterday. Opened today and only 5 of approximately 25 sheets remain

[scollette]

I have been building a worksheet for weeks now. I opened my document today and only 5 of my 27 pages remain. What does remain has to have the "F9" button pressed to calculate. It doesn't normally require that. It opens with everything calculated typically. I was able to open a previous version of the document that was from 4 days ago, but I have lost 2 pages of calculations unless I am able to recover the lost pages somehow. I saved the document and it shows to have saved yesterday right before I shut my computer down for the night. Has anyone ever had this problem before? Is there a solution?

[Werner_E]

What version of Mathcad?

If MC15 or below - had you autosave turned on? If yes, then there may be a more recent version recoverable.

[scollette]

I am using MC15 datecode M030. The autosave was not turned on. I corrected that this morning when I realized that it was off.

[scollette]

An update to this...I just got off of the phone with a PTC representative and he says that without being able to recreate the issue on command that there is really nothing at all that he can do. This very same issue has happened twice to me now and both times it deleted back to the very same spot. He didn't seem to think that it was possible for the problem to be within MathCad. He suggests that Windows is the one deleting the contents of my file and changing the "Auto Calculate" feature to be checked off when that feature is always on by default on my worksheets that I create.