From the AKN – https://knowledge.autodesk.com/support/revit-products/troubleshooting/caas/sfdcarticles/sfdcarticles/Clear-a-corrupt-damaged-C4R-model-from-the-system.html

and https://knowledge.autodesk.com/support/revit-products/troubleshooting/caas/sfdcarticles/sfdcarticles/Cloud-collaboration-corruption-for-one-user.html

and

https://knowledge.autodesk.com/support/revit-products/troubleshooting/caas/sfdcarticles/sfdcarticles/Location-of-journal-files.html

Issue:

A corrupt/damaged Collaboration for Revit model or outdated link is being accessed/cached and it needs to be cleared from the system.

Even after selecting “Reload From” within Manage Links, the cloud link still remains outdated and loads previous versions.

Causes:

If bad data is written/cached locally, it may need to be manually cleared in order to open or synchronize the model.
 
NOTE: If enough time is allotted, and the bad cached data is made obsolete by other user’s changes then the issue could be cleared, as Revit will get the new information (ignoring the old bad cached data).

Solution:

Identify the Project and Model GUID for the affected model:

Open a journal file recorded when the error was presented and find the error within the journal file.
Above the error, look for text which starts with CLD:\\{Project GUID with numbers and dashes}(Project Name)\{Model GUID also with numbers and dashes}(Model Name).rvt
Note down the Project GUID, the first part in the brackets {}, and the Model GUID, the second part in the brackets.

Identify the Collaboration Cache Root folder:

Below the line with CLD:\\ look for a line that starts with SLOG  Local=.
Make a note of the Collaboration Cache Root folder name after the CollaborationCache folder (it will be in all caps with numbers and or letters); by default this would be within:
C:\Users\%USERNAME%\AppData\Local\Autodesk\Revit\Autodesk Revit ####\CollaborationCache

Move the local copy of the model in the following path to another location (e.g. the Desktop)
<Collaboration Cache Root>\<Project GUID>\<Model GUID>.rvt
Move the central cache file in the following path to another location (e.g. the Desktop)  <Collaboration Cache Root>\<Project GUID>\CentralCache\<Model GUID>.rvt
Move the model folder in the PacCache to another location (e.g. the Desktop):
C:\Users\%USERNAME%\AppData\Local\Autodesk\Revit\PacCache\<Model GUID>
 
NOTE: Older versions of C4R stored the PACCache in “<Collaboration Cache Root>\<Project GUID>\PACCache\<Model GUID>”

Alternate approach, if you have access to a second system:

On the second system, open Revit.
Sign into your own A360 account.
Open the problematic model.
Copy the newly created CollaborationCache files from the second system to the original system (overwriting).

Alternate Sledge Hammer approach (this is easier but may break things again):
Rename the CollaborationCache folder.
 
NOTE: This would force all model data to be re-cached and there is the potential that whatever caused the initial corruption would re-occur either on this system or on another.