Question: I don't know what is wrong but suddenly KMeans from sklearn is not working anymore and I don't know what I am doing wrong. Has anyone encountered this problem yet or knows how I can fix it? from sklearn.cluster import KMeans kmeanModel = KMeans(n_clusters=k, random_state=0) kmeanModel.fit(allLocations)  allLocations looks like this: array([[12.40236 , 51.38086 ], [12.40999 , 51.38494 ], [12.40599 , 51.37284 ], [12.28692 , 51.32039 ], [12.41349 , 51.34443 ], ...])  and allLocations.dtype gives dtype('float64'). The scikit-learn version is 1.0.2 and the NumPy version is 1.22.2 and I am using Jupyter Notebook. The Error says: 'NoneType' object has no attribute 'split' The whole Error looks like this: AttributeError Traceback (most recent call last) <ipython-input-30-db8e8220c8b9> in <module> 12 for k in K: 13 kmeanModel = KMeans(n_clusters=k, random_state=0) ---> 14 kmeanModel.fit(allLocations) 15 distortions.append(kmeanModel.inertia_) 16 #Plotting the distortions ~\anaconda3\lib\site-packages\sklearn\cluster\_kmeans.py in fit(self, X, y, sample_weight) 1169 if self._algorithm == "full": 1170 kmeans_single = _kmeans_single_lloyd -> 1171 self._check_mkl_vcomp(X, X.shape[0]) 1172 else: 1173 kmeans_single = _kmeans_single_elkan ~\anaconda3\lib\site-packages\sklearn\cluster\_kmeans.py in _check_mkl_vcomp(self, X, n_samples) 1026 active_threads = int(np.ceil(n_samples / CHUNK_SIZE)) 1027 if active_threads < self._n_threads: -> 1028 modules = threadpool_info() 1029 has_vcomp = "vcomp" in [module["prefix"] for module in modules] 1030 has_mkl = ("mkl", "intel") in [ ~\anaconda3\lib\site-packages\sklearn\utils\fixes.py in threadpool_info() 323 return controller.info() 324 else: --> 325 return threadpoolctl.threadpool_info() 326 327 ~\anaconda3\lib\site-packages\threadpoolctl.py in threadpool_info() 122 In addition, each module may contain internal_api specific entries. 123 """ --> 124 return _ThreadpoolInfo(user_api=_ALL_USER_APIS).todicts() 125 126 ~\anaconda3\lib\site-packages\threadpoolctl.py in __init__(self, user_api, prefixes, modules) 338 339 self.modules = [] --> 340 self._load_modules() 341 self._warn_if_incompatible_openmp() 342 else: ~\anaconda3\lib\site-packages\threadpoolctl.py in _load_modules(self) 371 self._find_modules_with_dyld() 372 elif sys.platform == "win32": --> 373 self._find_modules_with_enum_process_module_ex() 374 else: 375 self._find_modules_with_dl_iterate_phdr() ~\anaconda3\lib\site-packages\threadpoolctl.py in _find_modules_with_enum_process_module_ex(self) 483 484 # Store the module if it is supported and selected --> 485 self._make_module_from_path(filepath) 486 finally: 487 kernel_32.CloseHandle(h_process) ~\anaconda3\lib\site-packages\threadpoolctl.py in _make_module_from_path(self, filepath) 513 if prefix in self.prefixes or user_api in self.user_api: 514 module_class = globals()[module_class] --> 515 module = module_class(filepath, prefix, user_api, internal_api) 516 self.modules.append(module) 517 ~\anaconda3\lib\site-packages\threadpoolctl.py in __init__(self, filepath, prefix, user_api, internal_api) 604 self.internal_api = internal_api 605 self._dynlib = ctypes.CDLL(filepath, mode=_RTLD_NOLOAD) --> 606 self.version = self.get_version() 607 self.num_threads = self.get_num_threads() 608 self._get_extra_info() ~\anaconda3\lib\site-packages\threadpoolctl.py in get_version(self) 644 lambda: None) 645 get_config.restype = ctypes.c_char_p --> 646 config = get_config().split() 647 if config[0] == b"OpenBLAS": 648 return config[1].decode("utf-8") AttributeError: 'NoneType' object has no attribute 'split' 

Answer: Downgrading numpy to 1.21.4 made it work again