Block preview not available

[fat.mongrel]

Is there a box to be ticked in order to see the bitmap preview of a block before inserting it???

When I am inserting a block I get as "preview" only empty boxes, I can not see the block I am about to insert, I can certainly insert the block with no problem. the only thing is that I do net see the preview!!!

[CADDmanVA]

Just a hunch, but is the setting check to save thumbnails upon saving in the PREFERENCES dialog? If it is, try WBLOCK'ing the block in question out, then insert it through the INSERT command (not drag-n-drop).

[fat.mongrel]

Nah...

Is not that, I can do that.

Is just that I've got a series of standard blocks to insert via the pull down menus (supplied by the manufacturer of the product) and I do not see them...
I can certainly insert them if I know the block name, but I get a blank preview! Not even a message saying "preview not available" (i.e. when the block has been created by an earlier version of AutoCAD). I just get a blank preview...

[jaberwok]

Perhaps the manufacturer saved them without previews? In which case, CADmanVA's answer is worth following up.