Software Upgrades

Upgrading application software can cause some interesting issues.

User settings are sometimes lost.
Features, and how to access them change.
Un-documented features may disappear.
The user interface often changes.
Usually, you cannot open files saved from the new version in the old version.

For network client software, you add into the mix that there may be different levels of OS patches installed.
If you have varying application software installed on the clients, you can have different versions of key DLL files on each PC.

This is just for starters, off the top of my head.

I am sure that Maxwell, and some of the other peers will have more variations to report.

Chas