Layout ... Has Details Placed On It, and Cannot Have Its Sheet Assignment Removed (Placing a Detail on a Sheet)

Issue

When trying to place a detail on a sheet, you saw an error message similar to the following:

Layout ... has details placed on it, and cannot have its sheet assignment removed.

Cause

The sheet where you were trying to place the detail is already assigned to a different drawing in the Sheet Index, likely with the same name.

Solution

1. Open the Sheet Index (available in our Project Manager tool) and delete the sheet listed in the error message.

In the example, above, the sheet in question is sheet L1.3, so we would delete that sheet.

2. Create a new sheet.

3. Assign the layout in the current drawing to that newly created sheet.

You should now be able to place the detail on the new sheet.