error when attempting to chat with bison model

[henosis-us]

Entered key for bison model and got this error when attempting to chat

Uncaught exception
Traceback (most recent call last):
File "C:\Users\matth\Documents\interesting\gpt-cli\gpt.py", line 236, in
main()
File "C:\Users\matth\Documents\interesting\gpt-cli\gpt.py", line 184, in main
run_interactive(args, assistant)
File "C:\Users\matth\Documents\interesting\gpt-cli\gpt.py", line 232, in run_interactive
session.loop(input_provider)
File "C:\Users\matth\Documents\interesting\gpt-cli\gptcli\session.py", line 168, in loop
while self.process_input(*input_provider.get_user_input()):
File "C:\Users\matth\Documents\interesting\gpt-cli\gptcli\session.py", line 160, in process_input
response_saved = self._respond(args)
File "C:\Users\matth\Documents\interesting\gpt-cli\gptcli\session.py", line 102, in _respond
next_response += response
TypeError: can only concatenate str (not "NoneType") to str
An uncaught exception occurred. Please report this issue on GitHub.
Traceback (most recent call last):
File "C:\Users\matth\Documents\interesting\gpt-cli\gpt.py", line 236, in
main()
File "C:\Users\matth\Documents\interesting\gpt-cli\gpt.py", line 184, in main
run_interactive(args, assistant)
File "C:\Users\matth\Documents\interesting\gpt-cli\gpt.py", line 232, in run_interactive
session.loop(input_provider)
File "C:\Users\matth\Documents\interesting\gpt-cli\gptcli\session.py", line 168, in loop
while self.process_input(*input_provider.get_user_input()):
File "C:\Users\matth\Documents\interesting\gpt-cli\gptcli\session.py", line 160, in process_input
response_saved = self._respond(args)
File "C:\Users\matth\Documents\interesting\gpt-cli\gptcli\session.py", line 102, in _respond
next_response += response
TypeError: can only concatenate str (not "NoneType") to str