invalid item error when 'send offer to buyers'

[gorepe15]

Why do I get an jutterly useless, unhelpful 'invalid item' error when I 'send offer to buyers'???!

Listing gives me the option to contact watchers then blows me out... useless..

[john1297576]

This offer does not give any details of WHAT listings this applies to. It may not apply to vehicles !!

I looked into this yesterday (I would never use it as watchers in many cases are not interested in buying, and would be like unsolicited mail, junk mail through the letterbox) and as I only have Auctions it does not seem to apply

[gorepe15]

If it doesn't apply to some categories (why shouldn't it?!) why is the option visible!? That really would be amateurish coding...