Long story:
This still cuts me up after 4 years because this woman got away with it.
At the time I was teaching Equality & Diversity classes to adults, was teaching Health & Social are to kids from all parts of the world and my wonderful Manager was mixed race (Nigerian/Yorkshire).
A young Asian woman started in our department and was put into Office 1 and over the next 2 months I had no contact with her, zilch, nada, zero and every other word you can think of just so you undertand.
It soon became clear that she was arguing with everybody in the office which eventually turned into 4 complaints and so after a month she was made to switch to Office 2.
Another month passed by with us hearing stories about this woman arguing with everybody and more complaints went in so the Manager decided to deal with her and have all the staff in one by one.
It came to my turn and I was asked about her but I had no contact with her for the 2 months, I hadn't even been in a position to speak to her because our paths had never crossed but I had seen her from a distance.
My Manager then said that all her problems arguing with other workers was my fault because I was a racist

I kid you not, a woman who I had never met blamed all her arguments with other people on me.
Anyway, the bosses knew it was complete BS but wouldn't do anything about it even though I wanted to take it further 'Just forget about it' but after 4 years it still eats at me that she could accuse somebody and not get punished for it.
Short story:
Young Asian woman blamed all her problems on me and then called me a racist when I'd never even met her.