org.luaj.vm2.LuaError: LuaTimeOutSandbox.loader:35 org.luaj.vm2.LuaError: #322:1 attempt to concatenate string and nil
stack traceback:
	#322:1: in main chunk
	[Java]: in ?
	at org.luaj.vm2.LuaValue.error(LuaValue.java:1056)
	at org.luaj.vm2.LuaValue.concatmt(LuaValue.java:3143)
	at org.luaj.vm2.LuaValue.concatTo(LuaValue.java:3111)
	at org.luaj.vm2.LuaString.concat(LuaString.java:300)
	at org.luaj.vm2.LuaClosure.execute(LuaClosure.java:323)
	at org.luaj.vm2.LuaClosure.onInvoke(LuaClosure.java:190)
	at org.luaj.vm2.LuaClosure.invoke(LuaClosure.java:183)
	at org.luaj.vm2.LuaThread$State.run(LuaThread.java:192)
	at java.lang.Thread.run(Thread.java:745)

stack traceback:
	LuaTimeOutSandbox.loader:35: in main chunk
	[Java]: in ?
	at org.luaj.vm2.lib.BaseLib$error.call(BaseLib.java:179)
	at org.luaj.vm2.lib.TwoArgFunction.invoke(TwoArgFunction.java:73)
	at org.luaj.vm2.LuaClosure.execute(LuaClosure.java:385)
	at org.luaj.vm2.LuaClosure.onInvoke(LuaClosure.java:190)
	at org.luaj.vm2.LuaClosure.invoke(LuaClosure.java:183)
	at org.luaj.vm2.LuaValue.invoke(LuaValue.java:1743)
	at net.luaos.tb.common.Loader.invoke(Loader.java:65)
	at net.luaos.tb.common.LuaTimeOutSandbox.callLuaWithStats(LuaTimeOutSandbox.java:76)
	at net.luaos.tb.tb12.Sandbox.callFunctionWithStats(Sandbox.java:166)
	at net.luaos.tb.tb12.Sandbox.callLuaWithStats(Sandbox.java:156)
	at net.luaos.tb.tb12.Sandbox.runLuaWithStats(Sandbox.java:140)
	at net.luaos.tb.tb32.IRLuaScriptRunner.run_returnWithStats(IRLuaScriptRunner.java:33)
	at net.luaos.tb.tb32.IRPitcher.runScript(IRPitcher.java:151)
	at net.luaos.tb.tb32.IRPitcher.pitchPair(IRPitcher.java:135)
	at net.luaos.tb.tb32.IRPitcher.pitchRun(IRPitcher.java:105)
	at net.luaos.tb.tb32.IRPitcher.pitch(IRPitcher.java:76)
	at net.luaos.tb.tb32.IRPitcher.main(IRPitcher.java:39)
	at irpitcher.main(irpitcher.java:8)