It's a bit disconcerting. 
Viewing post in Sileo: Tales of a New Dawn comments
This is a known issue related to the latest versions of the Ren'Py engine and is a false positive. We've made some changes which should make this less likely to occur which will be rolling out in next months update, but in the meantime rest assured it's a false positive and Sileo is safe to play.
More info here: RE: Issues with February Builds - Sileo: Tales of a New Dawn by Xevvy (itch.io)