Application Designer Error: “SPDP_XXXX has been updated by another user. (3,1)

We get this error when we try to save our project or pages etc. To resolve this error, clear the  application designer CACHE and reopen the Application Designer.

To clear Application Designer CACHE:
go to Configuration manager-->under "Cache Files" section-->Click on "Purge Cache Directories.." button.
OR CACHE directory is specified at "Directory" field. Go to Cache path and delete all files under that folder.
  

What are the Compare Flags in peoplesoft? Chnaged, * Changed, Unchanged and *Unchanged.

Compare Flags:
Unknown:  Object has not been compared or Object is a non-comparable object.

Absent: Object is not present.

Changed: Object has been compared and last update operator id is not PPLSOFT i.e it is modified by the user. Last update date time is greater than comparison release date.

*Changed: Object has been compared and last update operator id is not PPLSOFT i.e it is modified by the user. Last update date time is less than or equal to comparison release date.

Unchanged: Object has been compared and last update operator id is PPLSOFT. Last update date time is greater than comparison release date.

*Unchanged: Object has been compared and last update operator id is PPLSOFT. Last update date time is less than or equal to comparison release date.