Why do I see a yellow exclamation mark next to some of my dimensions or leader objects?
The marker is highlighting the fact that the object it was measuring / referencing has been deleted or disassociated. This is particularly using if using constraints or perhaps 3D model geometry. If this is not desired switch the Annotation Monitor off.
A new feature in AutoCAD 2013 is the Annotation Monitor utility which notifies the user if dimensions become disassociated from its related geometry. It is controlled by the system variable, ANNOMONITOR which can be turned off by setting its value to (0). If you are not familiar with system variables, this is done as follows by typing the system variable (case insensitive) at the command line and then changing the value.
Command: ANNOMONITOR (press enter)
Enter new value for ANNOMONITOR: 0
Other valid settings are;
2 -- Annotation monitor is on.
1 -- Annotation monitor on.
0 -- Annotation monitor off.
-1 -- Annotation monitor off.
-2 -- Annotation monitor off. However, automatically turns on (sets ANNOMONITOR to 2), when a model documentation edit or update event occurs.
Further information and details can be found in the AutoCAD help
The Annotation Monitor flags non-associative annotations with a yellow exclamation marker and a red plus (+) icon appears in the drawing status bar. The Annotation Monitor works on Dimension Objects including Leaders and Mleaders.
When changes are made to an object, for example a user has a 3D model which has been dimensioned and a decision has been made to erase (or modify it in another manner) a portion of that model. Once the model has been modified the dimensions for the modified entities are disassociated. That is when the user is notified with a marker placed next to the dimension and by the alert icon in the drawing status bar. When the user selects the marker a menu will appear with options to reassociate or delete the dimension.
Occasionally the markers will not display, use the DIMREGEN command to bring the flags into view.