Installed Acronis 2015 and I can no longer access my external hard drive

CAn you plug the drive into a usb2 port or use a usb2 cable?

There are only USB 3.0 ports on this machine and the USB cable to the Seagate external drive is designed for this drive and has no generic alternative. I fail to see why I would do this as the drive works fine on other machines I own and on any port I choose to use. Sorry for my confusion about your request.

Hello Dan,

welcome to our forum.

Can you please clarify when exactly the issue occurd for the first time (e.g. right after Acronis True Image installation or after first backup etc.)?

Is the disk recognized if you remove Acronis True Image from the machine? 

Does Windows disk management give any error message when you try to assign a letter to the disk?

Thank you.

This started right after doing the first backup. The drive is recognized by disk management but when you try to assign a drive letter to it disk manager says the operation failed and asks you to refresh and or reboot due to the console view is not up to date. doing either one of these things does not help. I uninstalled Acronis and the drive is still unrecognized on this computer and disk manager still spits the same error. Very troubling. Other USB drives work fin on this machine and the one that does not work on this machine works fine on other machines. the trouble is that the factory image I made when this machine and Acronis was new is not accessible at this time by this machine.

Hi Dan,

thank you for answers. The behavior looks very strange; at least I've never seen such issues before. Especially interesting is that the disk was at first recognized and could be even selected as backup destination. Are you sure that the problem occurred right after backup had been created? Were there any reboots or update installations? 

Anyway, I would suggest you booting from Acronis Bootable Media and checking if the disk is recognized. If it is, you will be able to access your backup and restore required data. If it isn't, you can temporarily copy the backup to another drive, reformat the disk in question and check if it solves the issue.

Thank you.

Hi Anna
I took this drive down to my server and copied the backup file to one of my larger storage drives. I am one of those twisted people with 12 Terabits of storage on the server in the basement. The server reformatted the drive without error. I took the drive back up to my living room and booted up the Allienware and plugged it in. The disk manager see's the drive but explorer does not. I get the same errors with disk manager that i received before when trying to assign it a drive letter or when i try to format the drive. So far no joy.
I always enjoy a day when you get to learn a new trick or solve a new problem. I took the extra step and uninstalled magic disk and it had zero effect on this issue. I did not think it would as I have allways used magic disk on every machine I have owned. I was a Beta tester on Microsoft's Flight Sim X program and that tool was recommended by them for that purpose to my surprise. Even though I have had Magic Disk installed on systems using Acronis in the past I was hoping to eliminate all possible issues to this problem. I am looking forward to any ideas you may have here. I am even willing to sacrifice another external drive for testing this issue if need be. I just feel that the drive is not an issue. I went ahead ans submitted the log file that the help utility within Acronis asked for. I am not sure if you have access to that information but I will do what I can to facilitate that information for us here.

Thank you again for your help here.

Any thoughts?

Hi Dan,

sorry for the delayed answer.

I've found your feedback with attached report in our database and will check it on Monday.
However, I'm still not sure that the issue is Acronis related. Would it be possible to temporarily remove Acronis from your machine and check if it changes anything? 

Thank you.

I am sorry I failed to reply to that aspect of your previous request. I have removed Acronis and there was no change to the issue with the external drive. In an effort to try and narrow this issue down I will use another drive and re-install Acronis perform another backup to see if the problem persists. To be honest I never considered the possibility that it was something other than Acronis as it is the only software that I have used with that particular drive but I am open to any possibilities here. At this point I am more curious than anything and do appreciate your input. I am not usually stumped by computer issues and now I have a fight on my hands. I will report back with my findings.

Thank you again for your time.

Your issue may be related to the Acronis snapman.sys driver. It was probably not removed from your system when TI 2015 was uninstalled. You need to run the Acronis cleanup utility to remove the Acronis drivers. https://kb.acronis.com/content/48668

Just a quick question on something which you probably have already covered. In Windows Administrative Tools choose Computer Management, then Disk Management. The drive may actually appear there, in which case you will need to reassign its drive letter. This happened to me on a number of occasions when using USB external drives and earlier versions of ATI. I never found any other solution than to reassign the drive back to its original drive letter every time it disappeared.

Armlabes I have run the disk management tool on that drive with no success. Read the first post it describes the simtoms found in the disk managment tool.
Anna I have reinstalled Acronis and ran the utility that builds bootable media and booted from that media. Once Acronis started from that media it would see the drive that was failing. I made a backup to that drive and rebooted. The system still refused to recognize that drive. I mounted another USB drive and booted from the CD to make a backup. Rebooted into windows and that drive remained accessable so I was unable to reproduce the condition found on the first drive.
Mustang I am going to try and use the cleanup utility that you linked too and I will report back with my findings.

Hi Mustang
I had read about this issue on a tech blog and looked over the registry data that they had posted and found no such registry entries to work with. However I wanted to go ahead with your solution just the same. After completing the installation of the clean up utility and running it my external hard drive is still not recognized by explorer. I can still see the drive with disk manager but can not format the drive or assign it a drive letter.
When I get a chance I am going to try and partition the drive with another utility or another computer. Wish me luck.

Thank you all for your efforts.

I am a new Acronis True Image 2015 customer. I installed ATI2015-6525 on a new PC (UEFI-based with an internal GPT 1TB HD), created a full PC backup using a new Seagate 3TB USB3 Backup Plus drive, and finally created the ATI boot media on a 16 GB Lexar flash drive. Before investing time and energy into transferring files onto my new PC from the old one, I decided to wipe the new HD and perform a mock recovery using Acronis to make sure I'd understand the process if and when I'd really need it for disaster recovery in the future. As has been described in this and related threads, the ATI2015-6525 build of the boot media did NOT recognize my USB3 external drive. I plugged the external drive into different USB2 and USB3 ports on my PC, but the result was the same. After reading others' experiences, I downloaded and installed ATI2015-5539 on a working laptop and created a new boot media based on this older version of ATI. Many thanks to Acronis for having older ATI2015 versions available for download. The older boot media recognized the USB3 drive and I was able to recover my wiped system, multiple HD partitions and all. The recovered PC is behaving well so far. I guess I'll keep the ATI2015-5539 boot media until Acronis provides an update.

Thank you all for sharing your experiences.