text dissapear in reader when I highlight or select a fragment.

Dear all, each time I select some text in the reader, the whole text dissapears and it appears some seconds later as it was being reloaded.

That makes endonote useless for working in the files and I have to work in the documents out of endnote.

Please, any advice about how to solve this?

Thanks in advence,

Regards, JC

I would contact Endnote Tech support.  You also should provide versions of Word/endnote and operating system and version.  How long is the document? all output styles?  Are you tracking changes?   Does it happen in all documents or just one?  The answers, especially to the last two, can help make suggestions as to your next steps.