I noticed that the following was opened in 2012 and closed in 2015
"Hi, I have a writer document with many equations. I opened the document and all my equations display as “Object XX” where XX is a number from 1 to the number of equations in my document.
If I double click on them, nothing happens. Usually the formula bar would appear. How can I get my equations back? I have 37 equations and I can’t start again."
However, the issue was not resolved. I am running Version: 6.4.5.2 and the problem still manifests itself. To replicate I guess you need to have a document including many formula embedded within.