If you've already done that, did you just perform a standard clone, i.e. If your Windows disk uses the GPT layout, it's set up for UEFI booting if it uses MBR, it's set up for Legacy BIOS booting. Normally it doesn't matter which mode you boot in, but the Fix Boot Problems operation actually does work differently based on which mechanism you used, so if you're trying to fix a Windows installation configured to boot in UEFI mode, you want to boot the Rescue Media in UEFI mode as well. The Rescue Media can be booted in either Legacy BIOS or UEFI mode. Was the source OS not booting from NVMe? If so, then you'll need to run ReDeploy on the clone to enable Windows support for NVMe. I did not format or do any Windows operation on the new drive. I installed the NVMe and booted to Win10. The ONLY drive connected is my original OS drive, the 850. I shutdown, disconnected the other drives (which I had left installed before, some HDDs), removed the 960, reconnected the 850. I could not get my windows install thumbdrive to repair it either. I tried the Macrium rescue repair three times, all with identical results. I had a red 'x' for 'Updating Partition Boot Sector' One of them (Master Boot Record?) had a green circle arrow symbol (as if it would take effect after a reboot?). I selected the Macrium repair boot option. It failed to boot, with a 'missing partition boot sector' message. I shutdown the computer and unplugged the 850 Evo (the original OS drive). It took just under 30 minutes and reported a success. I opened Macrium and ran the Clone operation. I installed the NVMe and booted to Win10. I did not format or do any Windows operation on the new drive.

I purchased, and installed, a Samsung 960 Evo (an NVMe M.2 card). My current OS drive is a Samsung 850 Evo (a 2.5' form-factor SSD). (Plus, I just updated my rescue thumbdrive with the latest PE.)

Macrium reflect clone to ssd