Unable to mine on testnet I want to try mining on testnet, I'm using cgminer and I got it working on the main network but when i'm runnig it on testnet I got (in debug mode):

] Testing pool http://127.0.0.1:18332
] Probing for GBT support
] HTTP request failed: The requested URL returned error: 500 Internal Server Error
] Failed to connect in json_rpc_call
] No GBT coinbase + append support found, pool unusable if it has no stratum
] HTTP request failed: The requested URL returned error: 500 Internal Server Error
] Failed to connect in json_rpc_call
] No Stratum, GBT or Solo support in pool 0 http://127.0.0.1:18332 unable to use


I've tried with the generate=0 and gen=0 options but it seems to have no effect.

Currently my .conf file looks like: 

testnet=1
server=1
txindex=1
rpcallowip=0.0.0.0/24
rpcbind=0.0.0.0:18332
printtoconsole=-1
debug=1


I'am running bitcoind version 130100.

It seems that many tuturials are outdated and that some options/features changed (like bitcoin core Removal of internal miner)Is there something that I've missed ? 

EDIT:
@lavajumper: actually you where right about rpcallowip, but in my case there were others rpcallowip definition and it wasn't the cause of my problem (0.0.0.0/24 leads to a 403 (unauthorized) error).

After upgrading the version of bitcoind (version 140100, protocolversion 70015), I was able to run it, (but during the blockchain verifcation, there were 500 errors too).

For now i'm stil not able to run it with bitcoind 130100, and i don't know why...
One possible reason may that with Bitcoin Core 0.13.1, it was mandatory to use SegWit-compatible mining software. When SegWit transactions are included in a block, a coinbase commitment to the witnesses is required by consensus rules. As the eventual selection of transaction in the block is done by the mining software, old mining software cannot be used to construct a SegWit block. On testnet, SegWit (BIP141) has been active since May 2016.

In Bitcoin Core 0.14, a change was made that permits old mining software to continue to operate. When such software is detected, Bitcoin Core will simply return a block template that excludes any SegWit transactions, alleviating the need for a coinbase commitment.