Updating block in autocad
You will see this warning if you select the block name from the list. Because of this reason, you save the block in master file.
You need to type the exact block name in the block name field. Whenever you need it, you can simply insert it to your drawing.
If you do it correctly, Auto CAD will ask you for confirmation to redefine the block like below. If you need to modify the block, then you will want to modify it in master file. To update the block definitions in your drawing, you need to insert the updated block to your drawing again.
Auto CAD will recognize that the block has the same name with existing block. Choose redefine block, and your blocks will be updated.
For a complicated drawing with multiple sheet layouts with multiple viewports and layer states, a quicker way could be to use design center and insert and redefine the modifies blocks from Master Block to the existing project drawing.
Open design center, select the masterblock drawing, select the block in design center, right click and select "insert and redefine." The old block in the project file is replaced with the one in the masterblock file.
And when you need to create similar objects in your drawing. A long time ago, the only way to edit a block is by exploding the block to simpler object.
This method of updating your blocks is a workaround that gets you there in a backward direction, but it will work.
If you try to insert the Master file into your current file, Auto CAD will use the versions of the blocks that are in your current file, thus not updating them.