Spreadsheet data disappeared, then reappeared, then disappeared again.

Spreadsheet data disappeared, then reappeared, then disappeared again.

I have a spreadsheet that has 9 tabs.  The tabs are still there but the data is gone.  I looked at it the other day and the data came back at some point but now it's gone again.

When I click the refresh button on the browser i get:  ERROR OCCURRED. - DOCUMENT NOT AVAILABLE.

I have other spreadsheets in the same folder that have not lost the data, nor do they give this error on the browser refresh.