Solved String Collection to Pages doesnt work with Spigot?

I wrote myself a method that converts a String Collection into an Array wich is splitted into "pages"
when i run it without spigot it works..
but whenever i run it with Spigot the method spits out "Error : null" instantly without going into its code
ErrorLog:

Code (171734errornullorgbukkitcommandcommandexceptionunhandledexceptionexecutingcommandblugotinpluginblugotapiv13atorgbukkitcommandplugincommandexecuteplugincommandjava46spigotjargit-spigot-3fb9445-fbb47e8atorgbukkitcommandsimplecommandmapdispatchsimplecommandmapjava141spigotjargit-spigot-3fb9445-fbb47e8atorgbukkitcraftbukkitv1_11_r1craftserverdispatchcommandcraftserverjava650spigotjargit-spigot-3fb9445-fbb47e8atnetminecraftserverv1_11_r1playerconnectionhandlecommandplayerconnectionjava1354spigotjargit-spigot-3fb9445-fbb47e8atnetminecraftserverv1_11_r1playerconnectionaplayerconnectionjava1189spigotjargit-spigot-3fb9445-fbb47e8atnetminecraftserverv1_11_r1packetplayinchatapacketplayinchatjava45spigotjargit-spigot-3fb9445-fbb47e8atnetminecraftserverv1_11_r1packetplayinchatapacketplayinchatjava1spigotjargit-spigot-3fb9445-fbb47e8atnetminecraftserverv1_11_r1playerconnectionutilsrunsourcefile13spigotjargit-spigot-3fb9445-fbb47e8atjavautilconcurrentexecutorsrunnableadaptercallunknownsource180_102atjavautilconcurrentfuturetaskrununknownsource180_102atnetminecraftserverv1_11_r1systemutilsasourcefile46spigotjargit-spigot-3fb9445-fbb47e8atnetminecraftserverv1_11_r1minecraftserverdminecraftserverjava747spigotjargit-spigot-3fb9445-fbb47e8atnetminecraftserverv1_11_r1dedicatedserverddedicatedserverjava399spigotjargit-spigot-3fb9445-fbb47e8atnetminecraftserverv1_11_r1minecraftservercminecraftserverjava678spigotjargit-spigot-3fb9445-fbb47e8atnetminecraftserverv1_11_r1minecraftserverrunminecraftserverjava576spigotjargit-spigot-3fb9445-fbb47e8atjavalangthreadrununknownsource180_102causedbyjavalangnosuchmethoderrorlibaryutilsstringstopagesljavautilarraylistiiljavalangstringatcommandhandlerslibarycommandhandlerfuntionslibarycommandhandlerjava65atcommandhandlerslibarycommandhandlerhandlelibarycommandhandlerjava24atcommandhandlerscommanddispatcherdispatchcommanddispatcherjava24atlibarylibarymainoncommandlibarymainjava56atorgbukkitcommandplugincommandexecuteplugincommandjava44spigotjargit-spigot-3fb9445-fbb47e815more (Unknown Language)):

 

here my code

Code (Text):

public static String[] StringsToPages(Collection<? extends String> strs, int pageSize, int page) {

        String[] strings = strs.toArray(new String[strs.size() - 1]);

        int rest;
        int pages = (strings.length - (rest = strings.length % pageSize)) / pageSize;
        String[] re = new String[pageSize];
        // if given page count is less than 0 or higher than page count it will
        // return the last page
        if (page < 0 || page > pages + 1)
            page = pages + 1;
   
        if (page == pages + 1) {
            for (int i = 0; i < rest; i++) {
                re[i] = strings[(strings.length - 1) - (rest - i - 1)];
            }

        } else {
        int e = 0;
            for (int i = (pageSize * page) - pageSize; i <= pageSize * page - 1; i++) {

                re[e] = strings[i];
                e++;
            }
        }

        return re;
    }

here is the code to test it

Code (Text):

public static void main(String[] args)  {

        ArrayList<String> list = new ArrayList<>();

        list.add("Line 1: " + false);
        list.add("Line 2: " + true);
        //there is no line limit.
                        //Collection, Pagesize, return page
        String[] arr = StringsToPages(list, 5, 1);
        for (String s : arr) {
            if (s != null)
                System.out.println(s);
            else
                System.out.println("empty line");
        }
    }

 

Update: i added a try catch block but i get an exception anyways.. wtf is this ?

 

Lol using it in the same class works.. nice