Today I upgraded to ArcGIS Pro 2.3. I opened an aprx file with a map series. Every data link is broken* and all the map series pages and layer definition queries are gone. WTF!?!?
*we have a drive with two separate top-level folders "PROJECTS" and "DATA." The file paths all say "M:\PROJECTS\DATA\..." after the upgrade.
Luckily, this project was from an imported MXD, so I can start over without too much hassle. Still, this ain't good!