optimization hash not found when loading network

[joAschauer]

Error in Optimization tab on productive server:

TypeError: 'NoneType' object is not subscriptable

File "/usr/local/lib/python3.10/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 535, in _run_script
    exec(code, module.__dict__)
File "/ptx-boa/ptxboa_streamlit.py", line 263, in <module>
    content_optimization(api)
File "/ptx-boa/app/tab_optimization.py", line 17, in content_optimization
    n, metadata = api.get_flh_opt_network(
File "/ptx-boa/ptxboa/api.py", line 287, in get_flh_opt_network
    hashsum = metadata["flh_opt_hash"]["hash_md5"]