Failed to save project - failed to load data - failed to Open Project

map-the-seabed

I'm having a reoccurring problem with ArcGIS Pro v3.0.3. For some unknown reason, the APRX will suddenly not allow File Save, or Save As operations, on neither the network drive nor on a local drive. When I try to reopen the unsaved .APRX I get an error to say "Opening the selected ArcGIS project failed. This project was saved using a newer version of ArcGIS Pro". 

Clearly an issue as the software is the latest version.

I also notice the table that I was last editing does not open - "Failed to load data. Error: General function failure".

For my own investigation I have done the following;
1. Built a clean project environment that has only two data links, (1) a PGDB that is stored in the same Pro project location on the network drive, and (2) an SDE connection. The ArcGIS Pro stores 20 APRX files each having around 20 Maps and up to 14 Layouts.
2. Built the same project environment on a local drive.

Working from the local drive did not give me errors during the 2-days of testing. Working with the project from a network drive is throwing intermittent errors. 

The problem here is a complete loss of an APRX file containing a set of project deliverables. Any suggestions, Esri?

map-the-seabed

Update for the community -  with the advice from Esri Support today, this issue has been identified as "BUG-000118431".

First discovered in 2018, what's causing the issue hasn't been identified. Other users have worked locally and from a network. Also nothing to suggest NAS drives present an issue. A very inconvenient mystery...