I keep getting an error when with tronpy trc20 token transaction - FIXED

Question

I keep getting this error whenever I try to send an trc20 token transaction with tronpy

Traceback (most recent call last):
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/flask/app.py", line 2447, in wsgi_app
    response = self.full_dispatch_request()
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/flask/app.py", line 1952, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/flask_cors/extension.py", line 161, in wrapped_function
    return cors_after_request(app.make_response(f(*args, **kwargs)))
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/flask/app.py", line 1821, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/flask/_compat.py", line 39, in reraise
    raise value
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/flask/app.py", line 1950, in full_dispatch_request
    rv = self.dispatch_request()
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/flask/app.py", line 1936, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/home/pgolphri/flask_app/app/api/routes/transaction.py", line 687, in create_token_wallet_transaction
    token.token.lower()
  File "/home/pgolphri/flask_app/app/tron.py", line 111, in create_token_transaction
    sender_address).fee_limit(Config.TRC20_FEE_LIMIT).build()
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/tronpy/tron.py", line 210, in build
    return Transaction(self._raw_data, client=self._client, method=self._method)
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/tronpy/tron.py", line 117, in __init__
    self._client._handle_api_error(sign_weight)
  File "/home/pgolphri/virtualenv/flask_app/3.7/lib/python3.7/site-packages/tronpy/tron.py", line 458, in _handle_api_error
    raise ApiError(payload["Error"])
tronpy.exceptions.ApiError: class java.lang.NullPointerException : null

Here's the code I am using. tested it on the nile network and it works well but cant seem to get it to work on the main

def create_token_transaction(self, sender_address, priv_key, receiver_address, value, token):
        private_key_raw = bytes.fromhex(priv_key.decode("utf-8"))
        private_key = PrivateKey(
            private_key_bytes=private_key_raw)
        contract = self.token_contract(token)
        decimals = contract.functions.decimals()
        value = int(value * 10 ** decimals)
        txn = (
            contract.functions.transfer(receiver_address, value).with_owner(
                sender_address).fee_limit(Config.TRC20_FEE_LIMIT).build().sign(private_key)
        )
        data = txn.broadcast().result()
        id = txn.to_json().get("txID")
        return {
            "txid": id
        }

Also the error occurs when trying to generate new id for the transaction from https://api.trongrid.io/wallet/getsignweight

FIXED: Basically the TRC20_FEE_LIMIT I was getting from my environment variable was a string and not a number so it was causing the error.