Monday, December 21, 2009


Today I was opening the Arch model (local) and got a ton of warnings regarding dimension strings that needed to be deleted due to their references being invalid. The dialog below was followed by two more dialogs and hundreds of deleted elements.


Unfortunately Revit doesn’t really do a good job at letting us investigate what the heck is going. A way to open a view and see the dimensions about to be deleted would be a good start.

At this point the only thing you can do is to click the Expand button and save the report to html so you can view it later. Unfortunately my project was issued for bid last week and we’re now working on some revisions, so losing all these dimensions is a big problem. The only thing that came to mind was a problem with the structural linked file. So once the project opened, I looked through the html file, picked an enlarged plan detail and opened it up. As feared, the grids and columns were missing, which took away the dimensions.

Now the silver lining is that I was the only one working at this time, so I quickly closed out and checked what was going on with the structural file. Someone inadvertently wrote over the central file while in the process of doing a save-as with this project to start a new one(don’t get me started on that!). So no wonder that dimensions all of a sudden had invalid references!

Lessons learned

  1. Keep a weekly pdf/dwf set so you can easily compare what was lost when things go haywire. Or kill trees and print on paper.
  2. When bad things happen, make sure everyone gets out of the project while troubleshooting. This prevents major loss of work. For example in this case if someone saved to central after deleting all dims, we would be in some serious trouble. Hopefully now all we need to do is restore the Structural model and re-open the Architectural local.
  3. Training, training, training (if you’re in management, this is the most important of all).

For Autodesk

  1. Give us a way to investigate and see what is about to happen to the model!!
  2. Give us a way to unload links while opening. This way we can keep working and not lose any dimensional references when links are messed up. Currently I’m on hold while we fix the problematic link and then re-open the local. My only option at this point is to close everyone out of the Structural model, rename the folder and then launch my local, thus preventing it from finding the link and only temporarily remove dimension references, rather than permanently.

EDIT: As reader “S” suggested in an email to me, you can unload the workset on which a Revit link resides (which is why it’s recommended that each Revit link is placed on a unique workset). This acts similar to unloading the link while opening the file. However if the problem file was a dwg for example and this was linked in a drafting view, there would be no way to unload it except by renaming the file or folder in which it resides using Windows Explorer.



Anonymous said...

#1 think I tell everyone is... never ever ever ever EVER "unload" a linked Revit file!

Dave Baldacchino said...

Sage advice, but sometimes it's needed for troubleshooting reasons as explained in this post. Users need to understand that if you don't want to see something, there are other correct ways of doing that, and unloading a link or closing a workset are not (might not) be the correct way of achieving that goal.

seandburke said...

Of course, you could tell them as a matter of course to copy/monitor the grids and dimension to the copied grids in the local file, not the linked one! Then if the model in unloaded...
It's one way of keeping a clear separation of responsibilities as well.

Ppppppp said...

yeah this happens to me a good bit and of course not all users even read the message, they just click ok and continue, then save, then your screwed

Dave Baldacchino said...

Sean, true. However we don't use copy/monitor for various reasons. First, we have structural engineers in-house and we're used to a linking approach. There are also a number of deficiencies in the C/M process (ex: will not report newly added grids automatically) so we opt for the direct approach through linking. The other problem is that with CM, you are forced to set your link visibility to By Linked View or Custom; By Host View would be impossible to use as you'd end up seeing both the grids in the link and in the host project. Sure, there are ways to control visibility (such as worksets) but to us it feels like the benefits do not justify the extra work. Thanks for your comments and tip though!

Anonymous said...

Hi Dave!

Thanks for pointing this out.

Also, I've recently started my own blog. It's very new and much of it is a work in progress.

I have added your blog to my blogroll, but I wanted to give you the opportunity to inform me if you'd rather I not provide the link.

Anthony Mason

Dave Baldacchino said...

Hi Anthony, I added your site under my Revit Architecture links and also to the Revit & BIM Reading Essentials. Good luck!

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