OBJ parser broken in some locales
The OBJ parser (and possibly the PLY parser, as suggested by some previous reports of this issue on the mailing list) expects numbers to match the current locale format. In many locales, this means that the parser chokes on files that use numbers formatted according to en_US/C (which is likely "most of them"). Conversely, the parser does not accept files written by a locale-aware program if run in the C locale. Since the OBJ specification does not seem to specify how numbers are formatted, and per the Robustness Principle, the parser probably should accept both. At very least, it should probably not be locale sensitive.
Possibly related to #15580 (closed).