The entire Trump family couldn’t put together a valid absentee ballot between them in the New York mayoral race held November 7. Daily News:

Officials at the city's Board of Elections said the President signed and dated an absentee ballot along with an application on Oct. 19, checking a box that said he would be absent from the city on Election Day.

First Lady Melania Trump did the same, submitting a handwritten form that had everything in capital letters.

But the First Lady did not sign the envelope she put the ballot in as required by BOE, so her vote wasn’t counted. [...]

Trump's daughter Ivanka also botched her ballot. It was filled out correctly, but she didn’t mail it until Election Day—which was too late to be counted, officials said.

Her husband, Jared Kushner, didn't mail his back at all, according to the board. [...]

Officials said the President’s ballot was fine. But that was before the Daily News pointed out to an official that the date of birth on his application was a full month off.

Trump, 71, was born on June 14, 1946, but his ballot application lists his birthday as July.