Hello. Sorry for english mistakes : I had a code working quite properly with unity 5.1.1f1 I just install the patch 5.1.2p1 Then, I have that error : Code (CSharp): UNetWeaver error: SyncVar [System.Int32 tableaux::TableauChoixOP] cannot be an array. Use a SyncList instead. The problem is obviously in a line where I had written that : Code (CSharp): [SyncVar] public int TableauChoixOP = new int; So I am googling the problem, as I am quite a begginer in Game Development : I find a few answer, but really not much. So I try to change my line with : (... ok. I was just about to copy past the line from monodevelop, I copy, I paste, ... that appears : ℼ佄呃偙⁅呈䱍倠䉕䥌⁃ⴢ⼯㍗⽃䐯䑔䠠䵔⁌⸴‰牔湡楳楴湯污⼯久㸢䠼䵔㹌䈼䑏㹙䘼乏⁔慦散㴠✠潍..etc Wtf. Another bug.) Anyway, the code I talk about is : public static SyncList<int> TableauChoixOP; I adapt a few thing, and now, I have that error : "UNetWeaver error: Exception :System.InvalidCastException: Cannot cast from source type to destination type." And that, even google can't find ANY clue which could lead to a little hope part of a single solution (yeah, even google). There is also a lot of text in that error, and nothing seems relative to my code. Please, could you tell me what happened and how does the SyncList works ? Thank you very much.