Squid

yes, because a write to the drive failed, so the OS automatically disabled the drive.  To re-enable you must rebuild the drive from the parity information
 
DO NOT FORMAT
 
Stop the array, unassign the drive 1
Start the array, stop the array
Reassign drive 1
Start the array and start the rebuild.

Nothing gets changed.  Caveat is going from 6.9+ back to 6.7 / 6.8 is that you will have to reassign your cache pools.  

You have the Dynamix Schedules plugin installed.  This adds another tab to the Schedules section which allows you to change the default times that hourly, daily, weekly, and monthly background task run at.

Try clearing out the history, cookies etc.  If that's Safari and still have problems, then try Firefox / Chrome and see if there's any change (not a solution, but would be a data point for the devs)

Groundwork has been laid in the soon to come 6.11 Stable release for 2FA on the actual logins to the server.  Not implemented as of yet, but the groundwork / infrastructure changes are now in place

Jan 29 04:47:51 Infinity kernel: mce: [Hardware Error]: Machine check events logged Jan 29 04:47:51 Infinity kernel: [Hardware Error]: Corrected error, no action required. Jan 29 04:47:51 Infinity kernel: [Hardware Error]: CPU:1 (19:21:2) MC11_STATUS[Over|CE|-|AddrV|PCC|-|CECC|-|Poison|-]: 0xd7894800017d60c0 Jan 29 04:47:51 Infinity kernel: [Hardware Error]: Error Addr: 0x0000000000000000 Jan 29 04:47:51 Infinity kernel: [Hardware Error]: IPID: 0x0000000000000000 Jan 29 04:47:51 Infinity kernel: [Hardware Error]: L3 Cache Ext. Error Code: 61 Jan 29 04:47:51 Infinity kernel: [Hardware Error]: cache level: RESV, tx: INSN  
Looks like it's a typical Ryzen MCE and nothing to worry about.

It's not Unraid per se, but the manufacturers of motherboards and devices themselves.
 
The timings etc on USB3 are more strict than on USB2 so the motherboards and devices (in particular) need to be higher quality.  Flash drives as an example are manufactured with the expectation that they will be lost.  If the manufacturer can save 1/10th of a cent on every stick made by substituting a different capacitor that *technically* hits the tolerances but may quickly degrade then it adds up to significant profit.
 
Lower tolerances = higher reliability.  Higher tolerances = lower reliability.  Q.E.D.

Settings - Docker with the service disabled

Does today's update to CA fix this?

Your flash drive is being mounted as read only due to corruption.   Toss it into a separate computer and run the file system checks on it
 
 
If problems continue replace it with a quality drive (kingston)

Yes you can do this.
 
For best results (ie: Trim Support) you would create cache-pools with the SSD's and only have a single flash drive (any size) as being part of the main array (Currently, the main array does not support Trim, and a disk has to be assigned to it -> hence the flash drive assigned)

Unraid has no "power saving" on the CPU unless you install the sleep plugin (which you don't have)
 
It would be worthwhile to not run your memory at an overclock (3000MT/s)  The memory you purchased F4-3000C15-8GVR is actually 2133.  Disabled XMP / AMP is the BIOS and also run a memtest from the boot menu for a minimum of a pass - If you're booting the OS via UEFI, you will need to temporarily switch to Legacy boot in order to run the test

Fix Common Problems - Tools, Update Assistant

Something happened on your flash drive.  Delete /config/plugins/community.applications.plg and /config/plugins/community.applications
 
Reboot and you'll be good to go after a reinstall

Yeah, that is going to be your entire problem.  Both the logs and CA's diagnostics show that the date is March 15, 2019 and SSL fails if the date is significantly out for security reasons.
 
Settings - Date & Time. set the correct date & time and also give the system a couple of ntp servers
 

AMD Ryzen 9 5950X 16-Core Processor  
Have you looked at this yet:  https://forums.unraid.net/topic/46802-faq-for-unraid-v6/page/2/#comment-819173
 
Specifically Typical Idle Power Supply Settings in the BIOS?
 
Also, for stability you should never ever run memory at an overclock.  You're running your memory with the XMP profile at 3200MT/s
 
It *appears* that you bought "generic" memory, since the Manufacturer and product number is "Unknown", but since 3200MT/s memory is exceedingly rare, you're more than likely running 2133, and should disable XMP in the BIOS.

Then you've done a symlink or something because the situation with emby is not actually possible. 

Click on each share (shares tab) and you can set the minimum free space.  It should however actually default to 0

Have you run Memtest from the boot menu at least a pass or two?  (If you're booting via UEFI, you will need to temporarily switch to legacy for Memtest to work)

Jul 6 23:12:49 Axiom mcelog: failed to prefill DIMM database from DMI data  
Primarily an informational warning, and safe to ignore.  A BIOS update might help though.

Is your reverse proxy allowing websockets through?  (It's usually an option)

Not necessarily your problem, but try running your memory at its rated speed of 2133 instead of it's overclocked XMP profile of 2666
 
In addition, run a Memtest from the boot menu

Segfaults are rather common with Plex.  You could run a memtest to rule out any memory issues, but the best place to complain about it is on Plex's forum

The above still applies - Within same share, the file stays on the same disk.  Different shares the destination will follow the use cache rules on the destination.  Using a rootshare file stays on the same disk

Yes
 
Via Dynamix File Manager (or alternatively Krusader).
 
If you have a parity drive, then under Settings - Disk Settings turn on Write Method: Reconstruct Write