Removed flag 'inplace=True' from test and fixed the bug for this case.

Author: PedroM4rques

pandas/core/internals/blocks.py

@@ -1682,6 +1682,8 @@ def where(self, other, cond) -> list[Block]:
 
         try:
             res_values = arr._where(cond, other).T
+        except OutOfBoundsDatetime:
+            raise
         except (ValueError, TypeError):
             if self.ndim == 1 or self.shape[0] == 1:
                 if isinstance(self.dtype, (IntervalDtype, StringDtype)):

pandas/tests/frame/methods/test_fillna.py

@@ -794,4 +794,4 @@ def test_fillna_out_of_bounds_datetime():
 
     msg = "Cannot cast 0001-01-01 00:00:00 to unit='ns' without overflow"
     with pytest.raises(OutOfBoundsDatetime, match=msg):
-        df.fillna(Timestamp("0001-01-01"), inplace=True)
+        df.fillna(Timestamp("0001-01-01"))