TCP connection crashes after reading only a few strings - sockets

Question

I'm working with the ESP8266 wifi module programming it in LUA using NodeMCU. I was able to connect from an iPhone app to the TCP server created by the wifi module to send 3 floats. I parse the huge string into 3 strings and send them using uart to and Arduino. It works just fine but after about 10 inputs it crashes/freezes. I need the constant flow of data to keep coming but consistently and I'm unable to do it reliably.
I've printed after each line to keep track of what is actually happening and even after that i'm still not sure what is going on.
Code
`
print("11\n")
wifi.setmode(wifi.STATION)
print("22\n")
wifi.sta.config("WDTS03","Walker14!")
print("33\n")
elWiFi =(wifi.sta.getip())
if elWiFi ~= nil then
print(wifi.sta.getip())
end
print("44\n")
if srv~=nil then
print("444\n")
srv:close()
print("555 \n")
end
print("Create server \n")
srv=net.createServer(net.TCP)
print("1\n")
if srv ~= nil then
print("srv !=nil \n")
srv:listen(6969,function(conn)
print("listening \n")
if conn ~= nil then
print("incoming\n")
conn:on("receive",function(conn,numbers)
print("2\n")
print(#numbers)
print("chekcing for nil \n")
if numbers ~= nil then
print("3\n")
p = string.find(numbers, "x=")
print("4\n")
q = string.find(numbers, "&y")
print("5\n")
if p ~= nill then
print("6\n")
if q ~= nil then
print("7\n")
x = (string.sub(numbers,p+2, q-1))
print("x=" .. x)
end
end --p ~= nill
print("8\n")
p = string.find(numbers, "y=")
print("9\n")
q = string.find(numbers, "&z")
print("10\n")
if p ~= nill then
print("11\n")
if q ~= nil then
print("12\n")
y = (string.sub(numbers,p+2, q-1))
print("y=" .. y)
end
end --p ~= nill
print("13\n")
p = string.find(numbers, "z=")
print("14\n")
q = string.find(numbers, " H")
print("15\n")
if p ~= nill then
print("16\n")
if q ~= nil then
print("17\n")
z = (string.sub(numbers,p+2, q-1))
print("z=" .. z)
end
end-- p ~= nill
print("18\n")
end --numbers ~= nil
print("54\n")
--conn:send("test\n")
end)
print("55 \n")
end
print("66 \n")
end)
print("77\n")
end
print("666\n")`
and I get the following output
11
22
33
44
Create server
1
srv !=nil
77
666
> listening
incoming
55
66
listening
incoming
55
66
listening
incoming
55
66
listening
incoming
55
66
2
338
chekcing for nil
3
4
5
6
7
x=0.1722259521484375
8
9
10
11
12
y=-0.7733306884765625
13
14
15
16
17
z=-0.5716094970703125
18
54
2
337
chekcing for nil
3
4
5
6
7
.
.--repeats a few times
.
y=-0.005340576171875
13
14
15
16
17
z=-0.9838409423828125
18
54
PANIC: unprotected error in call to Lua API (attempt to call a nil value)
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NodeMCU 0.9.6 build 20150704 powered by Lua 5.1.4
11
22`
It fails on the "conn:on" argument for "srv:listen" after a few times
Thanks for the help and sorry if formatting is messed up. First time

Answer 1

Too long for a comment, sorry.
PANIC: unprotected error in call to Lua API (attempt to call a nil value)
Hard to tell which value was nil/null. Create a Minimal, Complete, and Verifiable Example (MCVE) to reduce the amount of code one needs to analyze.
The following snippet will eventually lead to out-of-memory due to closed upvalues. Each of your callback functions should use its own copy of the passed socket instance rather referencing the one of a wrapping callback function. The third line should NOT re-use the conn variable but define one with a new name.
See https://stackoverflow.com/a/37379426/131929 for details.
srv:listen(6969,function(conn)
if conn ~= nil then
conn:on("receive",function(conn,numbers)
NodeMCU 0.9.6 build 20150704
Don't use those old 0.9.x binaries, they're outdated and contain lots of bugs. http://nodemcu.readthedocs.io/en/latest/en/#getting-started helps you get started with a new firmware.