Issue
Model corruption can happen due to a number of things. We have noticed a common trend about what causes these issues and have compiled them below to implement into office workflow in order to reduce the risk of corruption and down-time at work.
Cause
The typical error message you receive is the "the model is missing many elements, and it cannot be opened" (very common error message that pops up) and it usually stems from a corrupt family within the file.
Corruptions could be due to:
People working on the file are using different build numbers within the software version
- These micro up/downgrades cause corruptions.
- While we may think Revit 2020 is the same, Revit sees Revit 2020.1 differently from 2020.2 and saves the model up and down.
Too many warnings
- Minimize warnings to the best of your ability, especially the following warnings:
a. Highlighted walls are attached to, but miss, the highlighted targets
b. Highlighted elements are joined but do not intersect
c. Area or Room separation line is slightly off axis and may cause inaccuracies
d. Highlighted lines overlap. Lines may not form closed loops and it's variations
e. Stair errors.
f. Duplicate and Overlapping Elements.
Upgrading an old model/family
- Up until Revit 2016, there were certain elements that ended up getting their ID's changed in 2017.
- Things like fonts and stairs/railings, in particular, got changed and caused a lot of issues.
Exploded CAD files in the model - Avoid exploding/importing DWG's into Revit
- Ideally, you would link CAD files, and even better, create them in a container file.
- Use them as a reference underlay. Create what you need, remove the linked DWG file, create the family, and import the clean Revit family into Revit.
- Autodesk Article about Revit-CAD can be found here: Importing or Linking CAD Files | Revit | Autodesk Knowledge Network
Purge the model from time to time
- The model gets clogged up with items that are unnecessary and could cause issues. Slows the performance down as well. You can pick and choose what to purge or you can purge all. It usually requires purging 3x in order to get rid of everything in a model.
- It would be a good idea to "Compact" the model at the end of the week, duplicate it and archive one file. This way everyone can create locals the following week from a clean Central Model.
Solution
Overcoming the issue really depends on how deeply rooted the corruption is. Sometimes opening the model without Audit lets it open, from there you can save out families in order to test for corrupted families. There are also cases where opening the model without the "audit" box ticked lets you open the model and the error happens ever so often. If it lets you open it normally, you can then start to review what may be causing the issues and triggering the error.
When there are over 100 missing elements, generally speaking, Revit won't be able to open the file. This usually means there are a few corrupt families.
Here is a good in-depth article about corruptions as well which will explain the above in further detail: Crash Revit Crash - Fixing Revit Crashes. (linkedin.com)
Corrupt Linked Files
Sometimes, the corruption may come from a corrupted file that you have linked in. If this is the case, you may be able to force the model to open through trying to open certain worksets that don't contain the linked files (if your office workflow is to put linked files on separate worksets). Failing that, you can detach from central and move that local file into a different location to try and "break" the link. For example, if it's on your server, moving it locally will generally break the links. If the model opens without issues and no errors, it may be the linked files causing issues.
Load in the linked files one by one and test to see if you get the errors upon saving/closing/reopening.
Fixing Corrupt Families
If you are able to successfully open your model, you can check for corrupt families by "saving them out". Create a duplicate of the file and begin troubleshooting.
You do this family save-out through right-clicking on the "Families" within the "Project Browser" and clicking "Save". This will prompt you to save in an area on your computer. Personally, I create a new folder on the Desktop and then point the families to save into that. This way you can quickly find and delete the folder when done or delete contents if you need multiple instances of this process.
As the families are being saved out, you will begin to have warnings come up, most can usually be ignored unless it says "cannot be ignored". I would make a list of all of the messages that you receive so that you can review these families later. The family will be visible in the bottom left corner during this process. Make note of the name (case and space sensitive) and their errors to review later.
If the family is corrupt, it'll cause Revit to crash. Make note of that family in the bottom left corner and close Revit. Delete all of the families that successfully saved out into that folder, open up Revit, delete that family in the Revit file by clicking on "Families" again, but this time "Search" and type in the corrupt family. You can then delete this from the model and start the process again. Keep doing this process until Revit doesn't crash anymore.
Now that you have a list of your corrupted families, you can start to audit them one-by-one on their own. This time, instead of deleting it from your working file, reload the clean families into the file instead of deleting them. Sometimes these families weren't actually being used and have just been loaded in and left there. This is why purging is recommended. There are many cases where we see a corrupt family being in the file but only 1 instance of it, and purging deletes it and fixes the error.
External Resources
Crash Revit Crash - Fixing Revit Crashes.
Importing or Linking CAD Files | Revit | Autodesk Knowledge Network
AutoCAD and Revit File Sharing | Import Export Link (autodesk.com)