maggie33 wrote:Would save lot of time, if you had mentioned the use of a 16 port hub in your first post.
And i wonder, how it should be related with your update to sequoia 15.1?
Information that it happened after the OS upgrade would also have important to know,
because this is what changed from the one to the other day.
maggie33 wrote:Anyhow, i still wonder, why it worked before - but not now anymore with this (same) hub, etc. Would be just interesting to understand, what really was the issue.
What is the status now? Does it work after your proposed changes?
To exclude the USB Hub as root cause disconnect it from the Apple computer and connect ARC USB directly to the computer.
I suggest to do this this before making any changes to the OS because if you perform multiple changes (the OS upgrade and changes in the macOS settings) and it should still not work, then you do not know whether the root cause is still the OS upgrade or something that you changed later.
For the next proposals I realise that this will probably require external help...
But I just wanted to put this idea forward. Maybe something like this can be implemented for the future, because problems like this could happen from time to time after OS upgrades. You should be prepared for this so that you can get back to work quickly if necessary.
So, If this troubleshooting doesn't solve the issue...
Do you have a backup which restores the system to the day before the upgrade?
Under Windows I have a disk image based backup of the SSD with the operating system.
In would have resolved the issue in two steps
1. make a disk image of the current non working state after OS update for later evaluation on a 2nd / external boot drive
2. I would restore the disk image of the day before OS update
3 advantages here:
a) if everything works fine after restoring the OS before the update then you know that it is no hardware problem
b) you can work again
c) you can boot from the external drive at any time for any further troubleshooting.
Once you know how to solve it on the 2nd OS installation, then make a backup of current main system
and perform the OS upgrade again and then fix any potential settings problem in macOS.
Just as you have to wear a seatbelt when driving a car, you should also make sure that you have implemented a tested disaster solution when operating a computer which, in the event of a disaster, restores a working state, if possible without loss of user data (separation of OS, user data on several partitions or physical discs).
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