My setup is a little bit complicated and I'm almost sure that my problem is port related.

So I'm running Mac OS X 10.13.4 with Parallels Desktop with a Ubuntu 14.04 VM. I managed to setup bitcoin core in the VM, on top of it I installed c-lightning and managed to fund it with btc (All is happening on the testnet) which I used to open one channel with some random other node. Everything is perfect for now.

Because I want to use the LApp for WordPress Lightning-Publisher I Installed lightning-charge and started an HTTP server running on the default port 9112. All of my ports are correctly forwarded and in my bitcoin.conf file I have allowed all ips. If I run Mozilla in my Ubuntu VM and go to http://api-token:mySecretToken@localhost:9112/info everything is fine, but when I try this on my Mac I get Can't open the page because the server unexpectedly dropped the connection. If I try using my external ip it's the same thing.

Using several sites to check if my ports are correctly forwarded I get that all corresponding ports are open (18332 for BTC core, 9735 for c-lightning and 9112 for lightning-charge).

Here is my bitcoin.conf

testnet=1
server=1
rpcallowip=0.0.0.0/0
rpcuser=someuser
rpcpassword=somepass

addnode=104.237.131.138
addnode=151.80.205.132
addnode=192.155.82.123
addnode=74.220.255.190
addnode=80.100.203.151

here is my lightning config

network=testnet
alias=IVCHOBIVCHO
port=9735
rgb=008000

Proof that 9112 is open:

Proof that lightning-charge opens from inside the VM:

And in Safari on my mac (using localhost:9112 returns the same error):

Neither Ubuntu, nor my Mac are under any kind of Firewall. My router is TP-Link