David,
 You are in luck; P3e IS P6.  P6 used to be called P3e years ago when it was in Version 3.5, then Version 4.  Then came Version 5 (informally called P5) and then Version 6 (where it started being called P6.  With Version 8, it is now being called P6 Professional.
 You can open P3e XER backup files using either P6.2 or P6 Professional.  They are all the same program.  The specs requiring ‘P3e’ are just outdated.  Good luck!
Thanks Ronald, your help is
Thanks Ronald, your help is appreciated!
Thanks Ronald, your help is
Thanks Ronald, your help is appreciated!
David, You are in luck; P3e
David,
 You are in luck; P3e IS P6.  P6 used to be called P3e years ago when it was in Version 3.5, then Version 4.  Then came Version 5 (informally called P5) and then Version 6 (where it started being called P6.  With Version 8, it is now being called P6 Professional.
 You can open P3e XER backup files using either P6.2 or P6 Professional.  They are all the same program.  The specs requiring ‘P3e’ are just outdated.  Good luck!