Missing application ObjectDBX classes

[Anonymous]

I am working with Acad 2000.
I receive the following when opening. (*see attachments)

Missing Application: ObjectDBX Classes
Missing Application: AcDbDimAssoc

I believe this was created in a newer version of Acad.
The main problem is that I can not copy or paste any of the solids. They are similar to blocks, however- no blocks are listed in the .dwg
If I explode, all text becomes distorted. I am also not able to move, rotate or modify these in any way.
I can create a block, and it will work within this dwg only.
I am not able to wblock.

Does anyone have any advise?
I would like to be able to modify with having to re-draw.

Please advise...
Thank you!!!