I have created a v2 database (found in prefix.tar.xz) but when I tried to finally run it from an experiment, I got:

$ beat exp run amohammadi/amohammadi/iris-pad-with-train/1/iris-pad-with-train
Created cache path `/home/amir/idiap/git/beat/livedet2020-iris-beat-demo/prefix/cache'
Index for database livedet_iris_2020/1 not found, building it
Index for database livedet_iris_2020/1 not found, building it
Running `amohammadi/lbp-feature-extractor/1' for block `test_features'
Start the execution of 'amohammadi/lbp-feature-extractor/1'
Traceback (most recent call last):
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/backend/python/loader.py", line 123, in run
    return getattr(obj, method)(*args, **kwargs)
TypeError: setup() got an unexpected keyword argument 'start_index'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/amir/miniconda/envs/iris/bin/beat", line 11, in <module>
    sys.exit(main())
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/click/decorators.py", line 21, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/cmdline/decorators.py", line 92, in _decorator
    value = view_func(*args, **kwargs)
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/cmdline/experiments.py", line 780, in run
    return run_experiment(config, name, force, docker, local, environment, quiet)
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/cmdline/experiments.py", line 278, in run_experiment
    result = executor.process()
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/core/execution/local.py", line 360, in process
    loop_socket=self.loop_socket,
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/backend/python/execution/algorithm.py", line 166, in __init__
    databases=databases,
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/backend/python/helpers.py", line 248, in create_inputs_from_configuration
    end_index=end_index,
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/backend/python/database.py", line 184, in setup
    end_index=end_index,
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/backend/python/loader.py", line 127, in run
    six.reraise(exc, exc(value), traceback)
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/six.py", line 702, in reraise
    raise value.with_traceback(tb)
  File "/home/amir/miniconda/envs/iris/lib/python3.7/site-packages/beat/backend/python/loader.py", line 123, in run
    return getattr(obj, method)(*args, **kwargs)
RuntimeError: setup() got an unexpected keyword argument 'start_index'

^CException ignored in: <module 'threading' from '/home/amir/miniconda/envs/iris/lib/python3.7/threading.py'>
Traceback (most recent call last):
  File "/home/amir/miniconda/envs/iris/lib/python3.7/threading.py", line 1307, in _shutdown
    lock.acquire()
KeyboardInterrupt