Hello all,
I am trying to import UMLS ontology as defined in doc:
```
from owlready2 import *
from owlready2.pymedtermino2 import *
from owlready2.pymedtermino2.umls import *
default_world.set_backend(filename = "pym.sqlite3")
PYM = get_ontology("
http://PYM/").load()
CUI = PYM["CUI"]
concept = CUI["C0085580"]
print(concept.name)
print(concept.label)
```
while pym.sqlite3 exists and populated it doesn't load and script fails with
```
python test_onto_import.py
* Owlready2 * Warning: optimized Cython parser module 'owlready2_optimized' is not available, defaulting to slower Python implementation
Traceback (most recent call last):
File "test_onto_import.py", line 8, in <module>
concept = CUI["C0085580"]
TypeError: 'NoneType' object is not subscriptable
```
I only managed to run it once after load.
Locked
