Basics/2 test running forever: Missing comma?

My code solves all 3 examples in less than a second with "Run code", but with "Check Solution", Basics/2 runs forever and ends with ErrorTooLongForProcess. The test Basics/2 looks pretty much like the 3rd example:

result, message = checker(solver, ['...XXXXXX', '.XXX.X...', '.....X.XX', 'XXXX.X...',
                                   'XX...X.XX', 'XX.XXX.X.', 'X......X.', 'XX.X.XXX.', 'XXXX.....'],)
assert result, "3rd example. " + message

Some other users reported missing commas in some of the tests, is there a comma missing here (1st row) as well?

    solver(
    (u"...XXXXXX"
     u".XXX.X...",
     u".....X.XX",
     u"XXXX.X...",
     u"XX...X.XX",
     u"XX.XXX.X.",
     u"X......X.",
     u"XX.X.XXX.",
     u"XXXX.....",),
    WORDS)