Macrium Reflect 8 driver now being blocked by Windows

Newcad

A heads up for users of Macrium Reflect 8 - the last Free version of Reflect.

You may find that mounting of saved image backups is now being blocked by Windows.

In the latest Windows 11 update (KB5083769) Microsoft has explicitly revoked the driver (psmounterex.sys) for kernel loading via Code Integrity policy.

The driver is properly signed and still works, however Microsoft has added this driver to their Vulnerable Driver Blocklist.

Macrium are aware, but whether they will do anything about it is uncertain.
Reflect 8 is now deprecated and so no longer officially available or updated.

Officially you should upgrade to the latest Macrium Reflect X, which is not affected by the new block.
However Macrium Reflect X is paid for only, yearly subscription, with no Free version available other than a 30 day trial.

There is a workaround Registry tweak to disable the Vulnerable Driver Blocklist, if you are comfortable with editing your Registry.
However doing so will disable it for all currently blocked vulnerable drivers.
For the Pros and Cons of using that tweak, see this article on the Malwarebytes forum:

https://forums.malwarebytes.com/topic/335035-macrium-reflect-8-driver-blocked-psmounterexsys-cause-and-workaround/

RushEuro

There was an error rendering this rich post.

Newcad

I've now fixed the link to MB forum in the op.

PPSS I'm not keen on this new editor, especially on my phone where it does double lettering at the start of every line, eg. the PS at the start of this line.

Newcad

Macrium have now made an official statement about this image mounting situation, (and a seperate VSS error):

https://kbx.macrium.com/macrium-reflect-x/image-mounting-or-vss-errors-following-recent-windows-updates

It basically explains that what has happened only affects mounting images as a virtual drive and does not affect backup functionality.

It also points out the Reflect 8 is End-of-Life, so customers should install (and pay for) Reflect X.

I for one take that to mean that they are not currently planning to fix the mounting issue for Reflect 8 users.
Instead they are using this 'security' action by Microsoft's new block as opportunity to push them to update to (and pay for) Reflect X.

However as this blocked driver issue also affects Reflect LTSC, and SiteManager 8 for image mounting functionality, and those two are not EoL, then they are probably working on a solution for those two products which might then also be applicabe to Reflect 8.
We will have to wait and see.