Thanks Neil. I am working on V2021 and have SP1. I've updated my signature to include my imac specs. I have shut down, restarted the computer and nothing has seemed to help. I did start a new file and just drew a simple four walled box and tried placing the view>create interior view elevation and it worked. the only difference i see in the settings is the new file has the "configuration" set to section, whereas my existing file has it set to elevation. in both instances the pull down menu is greyed out so i cannot edit this.
do you think it has something to do with the room extents set by levels/stories? i'm perplexed...