The file doesn't match the format string -- it has a numeric value followed by two dates and who knows what else afterwards and you told it there was one date followed by three floating point values. Clearly that won't work...should be no mystery there.
First, unless the file is huge, just let readtable operate on its own; you have unambiguous date formats, it should have no issues interpreting the input unless there are ambiguities elsewhere in the file.
