Syntax error and crash in case of wrong magics

Input > histo
DEBUG:virtmat.language.interpreter.session_manager:main_loop: session model: <textx:session.Program instance at 0x7f4600bfa2c0>
Syntax error: None:4:6 --> - 10 histo* <--
Expected '(' or 'to' or ',|\)|='
Input > %histo
Syntax error: None:1:6 --> %hist*o <--
Expected EOF
DEBUG:virtmat.language.interpreter.session_manager:main_loop: session model: None
Traceback (most recent call last):
  File "vre-language/src/virtmat/language/utilities/errors.py", line 285, in wrapper
    return func(*args, **kwargs)
  File "vre-language/src/virtmat/language/cli/run_session.py", line 87, in main
    mgr.main_loop()
  File "vre-language/src/virtmat/language/interpreter/session_manager.py", line 596, in main_loop
    assert textx_isinstance(model, self.metamodel['Program'])
AssertionError

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "python-3.10.12/bin/texts", line 8, in <module>
    sys.exit(texts())
  File "vre-language/src/virtmat/language/cli/__init__.py", line 25, in texts
    clargs.func(clargs)
  File "vre-language/src/virtmat/language/utilities/errors.py", line 314, in wrapper
    raise RuntimeError('non-handled exception') from err
RuntimeError: non-handled exception