see attachement and stepts to reproduce
Steps to Reproduce:
1.Open an new document
2.Open the sidebar
3.Choose "Styles and Formatting"
4.Choose "Table Styles"
5.right click on any table style => modify
Fatal error (see attachement)
dialogue in order to edit the table style
User Profile Reset: No
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0
Created attachment 131083 [details]
fatal error report
*** This bug has been marked as a duplicate of bug 101648 ***