Problem with Network MAP Statistics

Hi friends, I'm practicing in my ratification environment and I came across the following problem: in the Big-IP GUI Network MAP takes some time to display some result and then presents the print error below. Can anyone indicate what might be happening? There has been no change in the environment that I believe may have influenced it. The version in use is BIG-IP v13.1.0.5 (Build 0.0.5).

 ![Image Text](/Portals/0/Users/191/39/360639/fig01.png?ver=2018-06-15-090538-680)