(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?
(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.
Living with P6 Databases - ronwinterconsulting
P6 File Corruption - ronwinterconsulting
If database is corrupted restoring last backup can be a lifesaver, only data after last backup will be lost. Data after last backup should be provided by the users, if backup daily or weekly not much might be required.
I do not use P6 but use a file synchronization software [FreeFileSync] that takes a single click and a few seconds to keep the backup updated as it only replaces updated files while the appdata folder is not included in my sync settings. I run it once a day.
The appdata folder is an important file, do not get me wrong, but it can be big and can make sync to take much more than a few seconds. If you have your software installation files and data files you can recover the most relevant if you ever have to restore your computer. In such case I have a preference on a fresh install.
But P6 database is a monster, it may be impractical to use external backup software or anything else other than what Oracle suggests.
Good Luck