Key not found

Hi,

 

I finished translating a file and when I was going to export it and send it to the client (20 minuties before the agreed time) I get an error message. Now the file appears as 100% translated but I cannot open it. I sent the sdlxilff it to the client and it was empty. Finally I had to redo the work in Word since Trados was not helping. Ths tranlation was niot saved to the TM either. What is the mistake? Whenever i TRy to open the file it says "Key not found. Nombre del parámetro: key"

I hope you can help me with this because I might have lost a client today and this is not acceptable.