BF: Fix TypeError

The ERROR constant was called instead of the error function.

Found by pylint.
ENH: Fix typo in error message
DOC: Fix typo in docstring
DOC: Fix typos in docstrings
DOC: Fix typos in source comments
DOC: Fix typos in source comments
Merge pull request #624 from philippwiesemann/fix-basevisual-typeerror

BF: Fix TypeError