If you haven't already, you should get the latest Datacad 18 update as it has the recently added symbol audit feature that allows you to use the symbol browser to browse all your symbol folders for possible corruption. Give it some time while it's working on folders, it's worth doing for sure to help avoid corrupting future files. Once you have audited all your symbols, set the value to False. Here is the info from the Revision History file.
Audit Symbol Files=TRUE
The default value is FALSE. This key should only be set to TRUE temporarily when you audit your symbol libraries, then set back to FALSE when you are finished. Leaving this key set to TRUE will increase the time it takes to display symbols in the Symbol Browser.
Setting this key to TRUE will cause DataCAD to scan Symbols for invalid geometry while browsing folders in the Symbol Browser. If an invalid entity is encountered, the entity is deleted from the symbol definition, the .DSF file is updated and a '.Audit' file is created with the symbol's name in the same folder. The number of updated .DSF files is reported on DataCAD's error line.
I would also use the new File, Repair tool on your base files if you haven't done that either.
https://www.datacad.com/update/downloads/RevHist/DataCAD/RevHist.html wrote:Enhancements to DataCAD 18.02.00 (Since 18.01.01):
AEC File Repair
A new 'Repair' option has been added to the 'idle' (no drawings open) File menu. When you open a file using this option, you will be presented with a dialog that includes the following options.
Drawing Database Tests:
- Invalid Entities in Drawing
- Invalid Entities in Symbols
- Duplicate Polyline Vertices
- Extraordinary Values
- Flatten 2D Entities
- Toggle off SWOTHLUDFBK
- Regen Screen on Load
The default drawing database tests, Invalid Entities in Drawing and Invalid Entities in Symbols, compares specific entity variables to 'absolute zero' (defined as 1.0E-12). When these variables, such as the radius of a circle, are so tiny (between 0 and 0.000000000001 32nd of an inch), they can prevent you from editing them, or cause DataCAD to crash. These 'garbage' entities are identified and can be deleted from the drawing database by the repair option.
The Duplicate Polyline Vertices option is self-explanatory and will automatically look for and remove duplicate polyline nodes.
The Extraordinary Values option will display a 'Z-Min/Max' dialog that will reveal Z values that are larger than 10,000,000 32nds of an inch (by default). So if any of your entities contain Z values less than -26,041.67 feet or greater than 26,041.67 feet, they will be shown. You can edit the variables for each entity manually, or you can 'flatten' them one by one, or all at once. You can change the minimum and maximum values then 'Rescan' to see if any Z values fall outside of the range you specify.
The Flatten 2D Entities option allows you to set all 2D entities' z-base/height values to zero. This includes 2D entities found in symbols.
The Toggle off SWOTHLUDFBK option is useful when a corrupt line type or hatch pattern is prevention you from opening your drawing. Disabling the display of hatch patterns and line types may allow you to open the drawing so you can reload the offending definition.
The Regen Screen on Load option can be toggled off if regenerating the display of your drawing is causing DataCAD to crash after it is loaded.
A '.Audit' text file with the same name as your drawing is automatically created and contains a report of your drawing's history and what type of entities were deleted.