Usually when drawing, many people will directly modify the existing drawings, which will lead to many hidden blocks not being cleaned up.

In this case, you can handle it like this (using Yao Chuang CAD to explain it as follows):

1. Create a blank drawing, then copy the drawing contents into the blank drawing, save the new drawing, and use the new drawing later:

1) Create a new blank chart:

Create a new blank chart

2) Copy the drawing contents to a new drawing and save it.

2. You can also use the purge command in the original file to delete unnecessary hidden blocks:

Clean up unwanted content.

Then save it.