hello.
I bought a mixbus license not so long ago.
I admit that I was not very satisfied with this purchase but I consoled myself by telling myself that at least I could use the XT harrison plugins on my ardour.
… and then on version 9.7, the XT Harrison plugins give me the message that they are in demo mode …
That was not the case on version 9.5.
what?
Ah, the plugins have been updated for upcoming MIxbus 12.
So you either need a plugin specific License or wait until MIxbus 12 [license] is available, or grab and copy the plugins from Ardour 9.5 and copy them to ~/.lv2/
Thanks for this very quick response. 
You say that I would be able to have to prevent a new mixbus 12 license to benefit from my harrison plugins that was part of my previous purchase?
Well…Weeeelllll… I will wait before getting angry and try to get into yoga… but withHarrison’s, it’s starting to do a lot of reasons to lose his calm…
Good… let’s stay calm: i will try your method to copy the plugins?
Thank you very much.
I copied the repertoire of ardour 9.5 as you said… and erased the directory on 9.7 and it seems well worked.
great. It’s nice.
I’ll still get into yoga in case I’m going wrong.
Thank you
I installed Ardour 9.7 while keeping Ardour 9.5 on my computer, and I opened a project that I had last saved in 9.5. Now I can see the XT plugins I inserted in 9.5, but they are missing the settings I had configured. At the same time, the plugin has been inserted again with the old settings.
How should I proceed without breaking anything?
Should I simply delete the instance that lacks the settings?
Thank You.
I have no explanation how this could have happened. The plugins themselves have not changed (other than the license check), so this hints at some bug with Ardour.
Do you still have the original session that you last saved with 9.5? Could you share it for investigation of that issue?
Sure, but where should I send it?
But I think I already saved the project using version 9.7. Still interesting?
Does it already have duplicate plugins?
The interesting project would be the one that didn’t have them
Should I load and save the project again using version 9.5? Where should I send it?
I took a snapshot of each song; where possible, I have one from before the update to 9.7, but I only saved one using version 9.7. All the others were saved using version 9.5. Should I send them?
yes, either per email to robin@gareus.org or if you can publicly share them please attach them to a ticket at https://tracker.ardour.org/ Thanks in advance!
…and when you load those in 9.7 the plugin(s) are duplicated?
Yes, the plugins will be duplicated. I’ll share the project with your email address via WeTransfer. Many thanks!
PS. In the “1 Back To Brooklyn 2 Gipsy Rides” session file the plugins are already duplicated.
…the mystery remains.
I opened “White Line Fever” as a test, and the plugins were duplicated there as well.
edit: I suspect it has to do with the fact that I kept Mixbus32C and all versions of Ardour from 8.2 onwards on my computer. But perhaps that isn’t relevant. I don’t know.
Yeah, that is however already in the “3 White Line Fever.ardour” session file. “XT-DC” is listed twice there for the relevant tracks. and that session is created-with="Ardour 9.5" modified-with="Ardour 9.5". So it looks like something went wrong saving the project with 9.5 (!).
e.g. For the Route with id="289" (“01 bd_02”) the plugin is added both pre-fader id="40060" and post-fader id="50077".
Loading the Session with 9.5 would also show this issue.
Highly unlikely, They are all self contained, besides I also keep many versions around to test. So you and me both 
/opt/Ardour-2.8.16_13591
/opt/Ardour-3.0_14207
/opt/Ardour-3.5.403-dbg
/opt/Ardour-5.12.0
/opt/Ardour-5.5.0
/opt/Ardour-6.5.0
/opt/Ardour-6.6.0
/opt/Ardour-6.9.0
/opt/Ardour-7.5.0
/opt/Ardour-8.12.0
/opt/Ardour-9.7.0
/opt/LiveTrax-2.0.79
/opt/Mixbus-10.0.0
/opt/Mixbus-10.1.164
/opt/Mixbus-11.0.291
/opt/Mixbus-11.2.237
/opt/Mixbus-2.5_14392
/opt/Mixbus32C-3.7.24
/opt/Mixbus32C-4.3.0
/opt/Mixbus32C-5.3.17
/opt/Mixbus32C-6.2.407
/opt/Mixbus32C-7.0.150
/opt/Mixbus32C-8.0.17
/opt/Mixbus32C-9.0.1
/opt/Mixbus32C-9.0.75
/opt/Mixbus-4.3.0
/opt/Mixbus-5.2.86
/opt/Mixbus-6.2.407
/opt/Mixbus-7.0.150
/opt/Mixbus-8.2.30
/opt/Mixbus-9.1.96
/opt/MixbusVBM-1.2.9
I’ve now loaded the project again in Ardour 9.5, deleted the post-fader XT-DC instances, and saved it. When I subsequently opened the project in Ardour 9.7, everything was fine—no duplicate plugins. Of course, I can’t rule out the possibility that I inserted the plugins twice myself during a moment of mental absent-mindedness. If that turns out to be the case, I apologize for the commotion I caused; I certainly didn’t mean to give you a shock! 
It will likely remain a mystery that is never solved. Right now, everything is running perfectly in Ardour 9.7.
Some more good news: Harrison relaxed the policy.
The change that the plugins need the latest MIxbus license was a mistake. With the next update the plugins will recognize the v11 license again. I am sorry for the inconvenience.