Click Sheets and Effects 
Hide all but the MISCELLANEOUS sheet.
Right click Sheets and Effects, click Move to Sheet.
Select entities to move from the MISCELLANEOUS sheet to appropriate sheets.
Repeat this until the MISCELLANEOUS is empty.
Click CC2 to CC3 conversion on the File menu to convert an old map you have opened.
This converts maps created in CC2, CC2 Pro and earlier add-ons into CC3 drawings sheets and draw tools. It moves entities, to the appropriate sheet by looking at their layers. Any entities on unrecognized sheets are placed on a new MISCELLANEOUS sheet.
When the conversion is over, we recommend that you:
Click Sheets and Effects
Hide all but the MISCELLANEOUS sheet.
Right click Sheets and Effects, click Move to Sheet.
Select entities to move from the MISCELLANEOUS sheet to appropriate sheets.
Repeat this until the MISCELLANEOUS is empty.
Show all the sheets. If any of your entities are obscured by other entities, you'll need to use Move to Sheet to move them above whatever it is that is hiding them.