Link tool not working

The hyperlink function has not been working properly for me for over a week now in WordPress. After selecting the text I want linked, launching the link window, and entering the url, I click on ADD LINK. Then it completely exits out of the post, taking me back to the POSTS page. No link was added, and it wipes out the post content that had not been previously saved. Please, please, please…for the love of God…fix this or let me know if there is something that I can do to fix it on my end. Thank you!