Hi Viveka,
I have the same issue with exporting AVI files using Revit 2018.3, from one computer but not another.
Both computers are running Windows 10 64 bit professional, so their operating systems are identical. Both have NVIDIA Quadro GPUs, but the newer machine (which will not export) has a different (newer) GPU. I don't think hardware is the issue.
On the problem machine the export AVI process does not prompt me for a compression codec when saving the file. I always use "uncompressed" when given the option. On the other machine (older) the export process includes that last pop up with the option to select a compression codec. I have successfully exported AVI from the same model with the older machine, but not the newer one.
When trying to export from the problem machine all the steps except the compression option are followed and Revit goes through the process of rendering the frames and generates a file but the file size is always 0kb (zero) and cannot be opened by video applications. At the end of the export I find that Revit has frozen and needs to be forced to close using Task Manager.
Why would two near identical machines have such different outcomes? Unfortunately it is not feasible to just use one machine for video exporting, but that is the current work around I am faced with.
Any suggestions gratefully received.
@Viveka_CD wrote:
Hi @Anonymous
I see that you are a new visitor. Welcome to the Autodesk community!
Can you make sure you have selected the view and walkthrough path? Please see step by step process in this article HERE
See video below on :
Revit Tutorials: Walkthrough
See Export options below:

Also, see the video below from 11:44 to see export settings, like length format (full frames etc)
Please select the Accept as Solution button if my post solves your issue or answers your question. Kudos welcome!
Regards,