That seems to be the main error but the full error message is [1mTraceback [m (most recent call last): 4: from playground.rb:42:in `<main>' 3: from playground.rb:42:in `p' 2: from playground.rb:42:in `inspect' 1: from playground.rb:42:in `inspect' playground.rb:42:in `inspect': [1mcannot set encoding on non-encoding capable object ( [1;4mArgumentError [m [1m) [m Thanks for your help in advance. Maybe it is because I need to combine the previous values of the types arrays with the additional values and not the previous values are set. What does the error mean and how to fix it? `ptl=[[0,3],[1,5],[2],[3,14],[4,0],[5,0],[6,15],[7,9],[8,7],[9,11],[10,16],[11,6],[12],[13,9],[14],[15,14],[16]] ptl.shuffle() str=ptl[0]+ptl[1]+ptl[2] cr=3 i=0 w=Array.new(2) { [] } until i==3 p ptl[cr] w[i]=ptl[cr] if ((w[i]&str).length()==0) i+=1 end cr+=1 end types=Array.new(19) { [[],[],[]] } pwt=w[0]+w[1]+w[2] types[17]=[[pwt],[str]] for i in 0..(pwt.length()-1) types[pwt[i]]=[[],[19]] end for i in 0..(str.length()-1) types[str[i]]=[[19],[]] end typeslist=Array.new(17) {|i| i } sampstr=Array.new(6) { [] } sampwk=Array.new(6) { [] } for i in 0..types.length()-1 typeslist.shuffle() for j in 0..5 sampstr.push typeslist[j] end for j in 6..12 sampwk. push typeslist[j] end types[0][i]=sampstr.push types[0][i] types[1][i]=sampwk.push types[1][i] types[2][i]=typeslist[13] end p types`