AutoCAD – Dealing with problematic, slow, crashing drawings

By Dennis Collin

Problematic drawings can be a real bane for any office using AutoCAD. The time lost for slow save and load times, crashing files or odd objects that stubbornly remain with a drawing, despite user’s best efforts.

The Drawing Recovery Manager is an invaluable tool to get users back on their feet after an AutoCAD crash. This command will run immediately once AutoCAD has been restarted after a crash. But, although it (usually!) finds the latest backup and temporary save files it doesn’t fix the underlying causes of the error. Therefore, if problems occur repeatedly its time to do a file health check and repair!

I am often asked why do drawings get corrupted? It can be down to several factors, failing hardware on the authoring workstation. From intermittent network issues to elements created by obsolete or poorly tested third-party add-ons, or perhaps even a computer virus! Bottom line is that these factors are often beyond the recipient’s control and a quick fast and simple fix is required to complete the job at hand.

Fortunately, the full AutoCAD and its LT sibling have a few tools that can hopefully resolve these issues.

The first to mention is the AUDIT command. This command is like a personal health check for your ailing drawing. Accessed from the application menu or via the command line the Audit command will check and fix, if prompted, various aspects of the drawing file. Upon completion it should report several problems found and fixed. Ideally this number should be zero. But if not, then the drawing should be saved, and the audit command repeated until this is the case. In most instances the drawing will be clean and report zero errors after two to three sessions.

Sometimes a drawing will report problems upon opening, or perhaps an external reference file doesn’t display in the main file or bind as an embedded copy. For this situation we also have the RECOVER command which like Audit, performs a health check on a drawing file but as the drawing is opened.

The RECOVER WITH XREFS command extends the regular Recover command as audits and repairs not just the host drawing, but all its reference files as well. This can be very useful midway through a project when file management and linking of data is at an advanced stage.

In some situations, problems persist. If this is the case another command that can prove useful is the WBLOCK command. This command is a little bit like the Windows copy and paste function and will write those select elements out to a new and hopefully cleaned version of your drawing.

Accessing Wblock can be either from the command line or the Insert tab of the AutoCAD ribbon menu. This will bring a screen which will grant users a range of options to transfer. I normally will use the ‘select objects’ option and write those elements to a new file, hopefully leaving the ‘corrupted’ aspects of the drawing behind. NB. Before doing this task ensure the appropriate layers have been switched on for selection, otherwise some critical information may be lost!

The copy and paste function are an alternative option to the WBlock command. For this to work, ensure the correct template has been selected to copy to. Select the desired elements, press ‘CTRL+C’ switch to the clean target drawing and paste (CTRL+V) and if coordinates are critical, use the paste ‘to original coordinates’ for consistency. If the standard Windows shortcut keys are unfamiliar then many of the options are available in a right click menu fly-out as shown below.

If all these attempts still yield no results, then our nuclear option would be the saving of the drawing file (assuming it can be opened) to an old R12 (DOS) version of DXF.

WARNING: Performing this task will mean that multiple layout tabs will be lost, as the R12 file format only supported one layout tab. Also be aware that any 3^rd part proxies, annotative elements, dynamic blocks and other elements will be simplified and/or deleted so it is strongly recommended to check this drawing post export to ensure that all required data has survived the trip. If necessary, once cleaned, the additional layouts and styles can be reintroduced by the Designcentre. If there is any doubt do make a backup copy first!

Bear in mind that this last method is rather extreme and should only be used as a last resort, but between these methods, I have been able to recover almost all corrupted drawings that are raised in support cases using a combination of all of these techniques.

A lot of these processes are covered both on our standard scheduled AutoCAD courses, bespoke workshops or ‘at elbow days’. For more details please visit our Cadline Training Website at https://training.cadline.co.uk/ to review course agendas or talk to a Cadline Representative on 01784 419922 where we will be more than happy to help and discuss requirements.