Can't save a old drawing with blocks/refs in it

I have a old drawing that I can open up, and everything will display on the screen. however there are some objects listed as block, but when I try to insert them, I get this error "The specified block can't be inserted because it's a external reference". The xref shows no reference in the drawing. The problem is that I if I make changes and save as new name, the objects the listed as blocks will show up in the new drawing. Any ideas?

I know this is a cumbersome way to do it,

but have you tried exploding them and then

re-writing them to a block name of your choice

Thanks. That works. A little bit more work, but it worth it.