I've encountered different exceptions since 4.0.0, and #446 didn't fix them. When I craft purposefully wrong inputs, I get less descriptive errors now:

Input: XMLSchema('aaaaaaaaaaaaaaaaaaaaa')
Before: XMLSchemaValueError: Invalid XSD schema file: Empty URI provided!
After: XMLResourceOSError: can't access to resource 'file:///path/aaaaaaaaaaaaaaaaaaaaa': [Errno 2] No such file or directory: '/path/aaaaaaaaaaaaaaaaaaaaa'

Input: XMLSchema('<<<<<<<')
Before: ParseError: Invalid XSD schema file: not well-formed (invalid token): line 1, column 1
After: XMLSchemaChildrenValidationError: Unexpected child with tag '{http://schemas.xmlsoap.org/wsdl/}types_wrong' at position 1.

I know that none of the error messages are perfect, but I think the old ones were more accurate, and the XMLSchemaChildrenValidationError looks like an f-string that missed the formatting. Is this a bug?