Luis Sequeira1 the Etrecheck WAS done before I removed chrome !
But folks it looks like I found the problem ! because I now have the session running fantastically ! So a little credit where credit is due... I think "chrome" was an issue but a small one that "piled on" so I am grateful for this info, because it's running better than ever!!
The real issue was with FCPX and specifically this session [I had edited a different session, with a different library] the night before and it worked OK.
the problem library / session had given me a warning a week earlier that it had been corrupted caused by a power failure [from a malfunctioning UPS] FCPX popped up a menu stating that one of the "project"s in the Library was corrupt and did i want to continue or open a backup. I decided to open the "backup" even though it meant I would lose a little work.
when I opened the Backup, FCPX could not find the "Proxies" so I was forced to relink them.
After re-linking all was well with the world, however now I had 2 libraries for one "session" and the corrupt Library was LARGE 1.8 Tb [approximately] so I closed the Backup session and opened the large, yet corrupt, original version of the session, I ran "Delete Generated Clip Files" and selected everything but "proxies" in an attempt to reduce the library file size... it worked.
so I closed the old corrupt session and re-opened the Backup version everything worked. BUT, bugged by the fact that I had still 2 libraries to run one session I decided to use a feature I've never seen before [which now I can't find?] but might only be available when running a FCPX [created] backup? I can't remember exactly what the menu selection was titled but it was something to tune of; "Copy Proxies to Library" so I tried... it fought me a little, I think I even had to restart FPCX but eventual I got that menu option to work... it took all day for the copy to complete. Once done, I thew out the corrupt Library then opened the back up and everything was there, no warnings and it worked...
or it looked like it did!
yesterday I went to do the edits to the now, official backup session, it opened and looked great BUT it was SUPER slow [as I described] and I posted on this forum for help.
I decided that the problem suggested to me, like there was something wrong with those "copied" "proxies" so on a whim I threw all "created library files" OUT [and BTW it did NOT warn me that this could not be undone as it always does...Hmmmm]
I went and re-created the proxies [similar to the way you create proxies when you first import the files] and I also set the size of the proxies creations to lower than the 50% default . it ran all night, [at 3am there was still 1/3 left]
This morning it runs FANTASTIC!
so the moral of the story... the "Copy proxies to Library" function appears to not work and that if you are forced to work from a "backup" copy of a "session / library' you are advised to re-create the proxies! [and not copy the proxies from the other library]
THANK YOU FOLKS!!! I hope you keep this posted for others to save them the grief... but I image few will find themselves in the same place I was?? [for the same reasons / actions ]?