ebayid:82 Failure | ErrorCode:21917177 

ShortMessage:Please enter valid dimensions for your package. 
LongMessage:Please enter valid dimensions for your package.


There are 2 common fixes for this:

Checking the dimensions in the "Shipping" section and make sure that if you filled out at least one of Length, Height, or Width, that you fill out all 3.

If, everything is correct there and the error continues, try setting your eBay Shipping Profile to "Don't Use Profile."