I started a while back and now I have 3 rooms in the Novice area, but I got up to level 4 so I wanted to claim another room, but now I get error -8 : You cannot claim more than 2 rooms in the Novice Area

Is this new?  What do I do to expand further?

Thank you for helping me. I'll work around it.

[5:29:29 PM]Hudson with energy 800 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:29 PM]Jordan with energy 700 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:29 PM]Mia with energy 125 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:29 PM]Wyatt with energy 650 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:30 PM]Hudson with energy 800 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:30 PM]Jordan with energy 700 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:30 PM]Mia with energy 125 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:30 PM]Wyatt with energy 650 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:31 PM]Hudson with energy 800 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:31 PM]Jordan with energy 700 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:31 PM]Mia with energy 125 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:31 PM]Wyatt with energy 650 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:32 PM]Hudson with energy 800 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:32 PM]Jordan with energy 700 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:32 PM]Mia with energy 125 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:32 PM]Wyatt with energy 650 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:33 PM]Hudson with energy 800 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:33 PM]Jordan with energy 700 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:33 PM]Mia with energy 125 attempting build on Spawn1(14925/15000) getting build code 0
[5:29:33 PM]Wyatt with energy 650 attempting build on Spawn1(14925/15000) getting build code 0

Seems to me like you can't construct the first spawn in simulation.

The log like RaskVann suggested:
[2:48:00 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:01 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:01 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:01 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:01 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:01 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:02 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:02 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:02 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:02 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:03 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:03 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:03 PM]Annabelle attempting build on Spawn1 getting build code 0
[2:48:03 PM]Annabelle attempting build on Spawn1 getting build code 0

Rewrote the code to be as simple as possible. Put this in the main loop:

    for(var name in Game.creeps) {
        var creep = Game.creeps[name];

        if(creep.memory.harvest) {
            var source = creep.pos.findClosestByRange(FIND_SOURCES);

            if(creep.harvest(source) == ERR_NOT_IN_RANGE) {
                creep.moveTo(source);
            }

            if(creep.carry.energy == creep.carryCapacity)
                creep.memory.harvest = false;
        }
        else {
            var target = creep.pos.findClosestByRange(FIND_CONSTRUCTION_SITES);
            var res = creep.build(target);

            if(res == ERR_NOT_IN_RANGE) {
                creep.moveTo(target);
            }
            else {
                console.log(res);
            }

            if(creep.carry.energy == 0)
                creep.memory.harvest = true;
        }
    }

Run simulation in Custom Mode and set out some sources and a construction site for spawn. Set out some creeps with MOVE, WORK and CARRY.

They will start building and build until they reach 99%. Then it will continue to log 0 (OK) to the console, but no more progress is achieved

I'm trying to build a spawn in Simulation mode, creating some creeps through the customize menu and making them harvest and build.

For some reason the progress on the spawn construction site stops at Progress: 14.9K / 15.0K

Whats even stranger is that the build command returns 0 (OK), but the animation is not displayed.

Can anyone help me?