Open the console on the machine and click the STATUS icon to see why the warning is occuring. As Markus inferred, it may be something as simple as an attached drive he added that is not being backed up.
Please check the belo w mentioned article link to resolve the issue.
This regarding Status reporting per logical partitioning you are having in your system where BESR 8.5 is installed.
Follow the article to customize it since in case if you are not backing up any particular logical partition then definitely your BESR home page console wil show you RED CROSS MARK mentioning at RISK . If the symbol appears with EXCLAIMATION Mark then its means attention required . Now Attention required may be due to several factors Primarily with space issue,etc.