I have have migrated all my Webcore pistons from the "User Webcore" to the HE Internal Webcore.
In trying to uninstall webcore using HPM but im getting the following
I tried everything including "repairing" the webcore instance and then trying to uninstall, but I get the same issue.
My Internal Webcore is just fine and all my automations are working but I wanted to clean my HE of the unused user webcore instance..
HPM manages the Apps Code and the Driver Code not Apps and Drivers. The error is telling you that the code can't be deleted because it is in use. Look in Apps and note that you have a WebCoRE app that is using the HPM installed code. You'll see (user) after the name in the Type column. The "fatal error" is that the code is in use and can't be deleted as is. You have to quit using the code (by deleting the App) before HPM can delete the code.
You'll get more clarity by going into Apps Code and attempting to delete WebCoRE.
Thanks for the help... i tried that but unfortunately same result.. heres what my "Apps" list looks like :
So upon initiating HPM Uninstall, I see this :
and after I run the HPM Uninstall, I get this :
any advice or thoughts ?
Easiest way to handle would be to use the HPM Unmatch, and then manually delete the app and driver code (which you would have to do anyway).
OK will try HPM Unmatch but i assume you mean the HPM Match Up, under the HPM app.. I assume there would be a follow on unmatch option.
It's under the HPM Settings section....
that appears to have done it... now I dont even see the Webcore (user) instance on the uninstall option for HPM..
For my own knowledge, what exactly did I do by unmatching.....
Thanks so much for your advice and guidance btw..
HPM has its own DB of apps and drivers that were selected during the very first MatchUp plus any subsequent Installs or Modifies, minus any Removes. The DB is shown when you look at View Apps and Drivers. It is a list of code that HPM is expecting to manage. If you remove the code manually, which appears to be the case, HPM isn't going to know. It will still think the code is on the Hub and can be managed.
UnMatch is a way to let HPM know, after the fact, that the code got manually removed and to stop trying to manage it.
Unmatch is almost the same as the remove, but with less checks against the code.
thanks for the explanation guys !!
and, of course, for resolving my issue.. truly appreciate all the quick support and I am always humbled by the knowledge of the members like yourselves.
I have this issue and have new C8 Pro.....but do not see the Unmatch option under the HPM settings.....what am I missing?
Click on Package Manager Settings and at the bottom of that page is UnMatch.
Nope, I don't have that option this is what the very bottom of my HPM Settings looks like. 
I ended up just deleting the previous HPM Webcore install (I disabled all my pistons), then was able to access the settings and remove the app, then deleted the app code. I then installed the native Webcore application and restored my pistons. Took some time, but I appea to be back up and running now and no longer have the nagging HPM "application upgrade" notice for Webcore.
Still no idea why I don't see the Unmatch option under HPM :-(.
My first reaction is that you are on an old version of HPM. Perhaps even the original version that Dominic left behind 
One of the first changes I added was a display, on every page, HPM's version:
It's always in the upper right section of a page, so if you don't even see the version, you're using 1.8.2 at best. According to the edit history:
csteele v1.8.6 Un-Match added
That's about 9 versions back
Yup v1.8.3 
Upgraded and now it I have the option. Thank you! 
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