Drawing Corruption Explained
If you see an Infection detected! message, your drawing is corrupt. The corruption is originating from on the of the files you've brought in as an external reference (Xref).
In the example to the right, the drawing includes an Xref that contains a dangerously high number of corrupt objects – 35,212, to be exact.
What to do if you see the Infection detected! error message
Drawing corruption may very well be the bane of CAD users' existences. Though not technically a virus, corruption in a DWG file has a similar result: slow performance, unopenable files, and, at worse, completely lost work. So what exactly is drawing corruption?
This article provides an in-depth description of corruption originating from your Xrefs, and what it does to your drawings. Go to the following links to find out what to do about it:
- Prevent drawing corruption in the future. See our Preventing Drawing Corruption page.
- Up against a deadline and need to fix a corrupt drawing right now? See our Drawing Cleanup Instructions.
Drawing cleanup: Ignore at your own risk!
Cleaning your drawings will take time – you cannot avoid this. But trust us: You'll lose much, much more time to a corrupt drawing than you'll spend cleaning your drawings – including all Xrefs. You have a simple decision to make, right here, right now: Spend some time to understand and implement drawing cleanup practices, or spend far more time at a far more inopportune moment to deal with recreating entire drawings. The choice is yours.
Causes of Drawing Corruption
Drawing corruption is not an issue that originates with our software, although you might certainly encounter it when using our software. It's the result of AutoCAD objects that can be present in any drawing, and often originate in files created by consultants outside the realm of landscape architecture and irrigation design, which you then Xref into your plan. (If anything, it's our software that is detecting and warning you about this potentially devastating issue.)
Although we understand it can be somewhat irritating to see a warning about drawing corruption pop up time and time again when you open a drawing file, we assure you that it's anything but a nuisance. It's a legitimate warning that, at any point, any number of the Land F/X objects in your drawing set may become nothing more than plain AutoCAD entities – that is, lose all their assigned data. We have had clients with entire sheet sets of detail callouts wiped out in this manner, for example, as the common Xref was present in all sheet files. Others have had seemingly random numbers of plants suddenly stop being plants. Or entire irrigation plans that were now unresponsive. That's hardly a loss in functionality – it's a virus-like issue that can cause literally days of downtime.
The hope is that we can instill an appreciation (and healthy fear) of the massive cost associated with needing to re-create an entire plan. Even if it takes an hour to locate the source of drawing corruption and address it, it's time well spent – plus it's a fraction of the time required to reverse the effects of a massively corrupt drawing.
Drawing corruption is caused by objects that should not be in your DWG files, such as:
- RegApps
- DGN linetypes
- Proxy objects
- Layer filters
- Scale list entries
- Shape definitions
The presence of these items causes sluggish performance and myriad other issues. In some cases, you won't even be able to open or save a corrupt drawing file.
How and Why Corruption Happens
The key idea to keep in mind is the very nature of the DWG file format (the format in which AutoCAD drawings are saved). In short, it's a rather archaic standard. Most modern computer file systems use multiple levels of data validation and auditing, making processes like those described on this page unnecessary. But the DWG file format is a holdover from many years back (1981!), and Autodesk has chosen to not address some key issues regarding data validity.
As a result, RegApps, Proxy Objects, DGN linetypes, and other problem-causing entities can enter your drawings – almost always from Xrefs – and wreak havoc. In fact, corruption can spread from one drawing to another when you simply have both files open.
At any point, a DWG file may become damaged to the point of being a total loss. It's important to note that Land F/X does not cause or spread drawing corruption. It's an issue that's inherent to AutoCAD and DWG files. We just recognize the imporance of avoiding corruption, so we've engineered our software with the ability to detect and eradicate it.
Remember: You can avoid drawing corruption by:
- Cleaning individual drawings, including all Xrefs and detail drawings within them
- Adapting drawing corruption prevention as your office standard
Corruption-Causing Entities
Remember: Land F/X does not cause or spread drawing corruption. We just detect it and help you get rid of it.
Several items can cause drawing corruption. Here are a few:
Quick video
RegApps
Registered Applications, commonly called "RegApps," are a method of adding data to objects in AutoCAD. In fact, the basic functionality of Land F/X relies upon the RegApp system. However, a flaw in the RegApp system can caus files to fill with excessive RegApps.
If you've seen the common Infection detected!, error message pictured at the top of this article, you can generally assume that your drawing is corrupt, the corruption is caused by RegApps, and, in almost all cases, those RegApps are actually in the external references, or Xrefs, attached to your main drawing. Xrefs can range from simple site images to entire DWG drawings. Most commonly, an Xref containing excessive RegApps will have come from a civil engineer.
When a nominal number of a few dozen RegApps balloons to tens of thousands, it can cause serious harm. The most common symptom of an Xref with excessive RegApps is that, when you select an object in your drawing, the highlight grip points do not appear right away, and the drawing appears sluggish.
The corrupt objects will almost always be in drawing files you're using as Xrefs. To ensure that you delete all corrupt objects from your drawing, you'll need to delete the RegApps from all your Xrefs.
The damage from excessive RegApps can be much greater than just some slowness. If the RegApp system becomes harmed, it runs the risk of rendering Land F/X objects into "dumb" objects. We've had drawings submitted in which hundreds of plants, callouts, and irrigation symbols have all reverted to just being plain blocks, and are therefore unrecognizable by the Land F/X system. As you can imagine, this is is a staggering loss and should be treated with all due diligence. Want to know why? Here's a handy guide that helps illustrate the risk:
To get rid of unnecessary RegApps, you can either:
- Complete our drawing cleanup steps on the drawing, all Xrefs, and any details you've placed in the drawing or Xrefs, or
- Run the DelRegApps command – also within the drawing, all Xrefs, and any details you've placed in the drawing or Xrefs.
Quick video
Proxy Objects
Some versions of CAD are unable to read certain items that are created in others. For example, we're able to make F/X CAD as efficient and affordable as it is by taking out the ability to read 3D renderings created in, say, CAD Civil 3D.
When CAD is unable to read one of these objects, it replaces that object with a Proxy Object – essentially an impostor that, in many cases, you won't even be able to see in your drawing. Nevertheless, Proxy Objects can create chaos in your drawings, slowing their performance and bogging them down.
You can prevent corruption from Proxy Objects by completing our cleaning your drawing and all Xrefs.
DGN Linetypes
"DGN linetypes" refers to linework created in MicroStation. For detailed information, see our DGN Linetypes page.
Our drawing cleanup steps will remove any and all DGN linetypes from your drawing and Xrefs.
Related Webinars
- Drawing File Cleanup: Addressing DWG Corruption: Drawing corruption is a major source of headaches and lost work for CAD designers. We walk you through the process of cleaning your drawings and show you some effective techniques for detecting and troubleshooting corruption when it strikes. (1 hr)
Contact
- Land F/X
Our software tailors AutoCAD® to the needs of landscape architects, irrigation designers, and other professionals. We automate your most tedious tasks and ensure accuracy, giving you more time to design.