Help! Drive is missing from Acronis Clone Disk

Lincoln, welcome to these public User Forums.

There are several reasons why your new M.2 SSD might not show up!

First, the new SSD might not be initialised.  It needs to be initialised in GPT to be used as a Windows OS boot drive, which in turn requires that the OS & Acronis Rescue Media be booted using UEFI BIOS boot mode.

Second, the type of rescue media being used may not have device support for NVMe M.2 drives, this is why the drive isn't found when you start a clone from within Windows and a restart is required.  The restart launches the PC into a very small Linux kernel OS which doesn't have the needed support.

Linux is used as the default for ATI 2015 rescue media, along with Acronis Startup Recovery Manager and any restart from Windows.

Typically, the recommendation for rescue media dealing with NVMe drives is to create and use Windows PE rescue media, which is much easier with later versions of ATI where this is now the default for rescue media created within the application (from ATI 2018 onwards).

If you have purchased the new SSD from Crucial, then you may want to download and use the OEM version of ATI that they can provide, which should be based on a much newer version of ATI than your 2015 one.  Probably based on ATI 2020.

One very important point: Please make a full disk backup of your working SSD to an external drive before doing any further attempts at cloning!  This is your safety net in case of anything going wrong, mistakes etc!

See KB 48338: Acronis True Image 2015: Creating Acronis Bootable Media for guidance.

KB 59877: Acronis True Image: how to distinguish between UEFI and Legacy BIOS boot modes of Acronis Bootable Media

KB 56634: Acronis True Image: how to clone a disk - and review the step by step guide given there.

Note: the first section of the above KB document directs laptop users to KB 2931: How to clone a laptop hard drive - and has the following paragraph:

It is recommended to put the new drive in the laptop first, and connect the old drive via USB. Otherwise you will may not be able to boot from the new cloned drive, as Acronis True Image will apply a bootability fix to the new disk and adjust the boot settings of the target drive to boot from USB. If the new disk is inside the laptop, the boot settings will be automatically adjusted to boot from internal disk. As such, hard disk bays cannot be used for target disks. For example, if you have a target hard disk (i.e. the new disk to which you clone, and from which you intend to boot the machine) in a bay, and not physically inside the laptop, the target hard disk will be unbootable after the cloning.

See also forum topic: [IMPORTANT] CLONING - How NOT to do this - which was written after dealing with many cloning issues in the forums. 

KB 58006: Acronis software: NVMe drives in RAID mode are not detected by Linux-based bootable media and Acronis startup recovery manager