Acronis Backup Cloud Known Solutions

Your Acronis Backup Cloud quick troubleshooting kit. Below are the most recently published and the most popular articles. The solution you are looking for is most probably right here.

Most recent articles

After changing the archive format from 11 to 12 the replication to cloud starts failing

You have a backup plan with 1st location in a local storage and 2nd location in the cloud. Format 11 is selected in the backup plan options.

After you have changed backup format from 11 to 12, replication to cloud starts failing with this error message:

| error 0x400001: The archive is invalid or its type is unsupported.
| line: 0x98130db273d2482
| file: e:\381\enterprise\backup\archivers\is\archive.cpp:153
| function: Backup::ISArchive::Open
| $module: disk_bundle_vsa64_12960

Installation fails with the error "MainEngineThread is returning 1632"

You install the backup agent in a Windows operating system. Installation fails with these messages in MSI log (C:\ProgramData\Acronis\InstallationLogs\BackupClient.msi.log):

MSI (s) (6C:34) [17:13:02:292]: Note: 1: 1336 2: 3 3: C:\Windows\Installer\
MSI (s) (6C:34) [17:13:02:292]: MainEngineThread is returning 1632

Backup to a network share or a removable drive fails with "The end of the file has been reached"

You are saving backups to a removable drive attached to the protected machine or to a network share that resides on a removable device.

Backup fails with this error:

Error code: 2
Module: 4
LineInfo: 0xC1C09B38BAFA76A0
Fields: {"$line":"484","$file":"e:\\627\\core\\file\\windows\\win32_dir.cpp","$module":"isk_bundle_vsa64_15300","$func":"win32_dir::letter_iterator::Find"}
Message: The end of the file has been reached.

SQL and Exchange DB/MBX backup plans do not run on schedule

You have a backup plan of Microsoft SQL or Microsoft Exchange databases or mailboxes.

Later, you have revoked and reapplied application backup quota from this machine or have changed tenant licensing model.

Now these backup plans do not run on schedule, while other backup plans still run as scheduled.

'Backup is missing' alert from a backup plan applied to a Hyper-V replica VM


You have a backup plan applied to a Hyper-V replica VM, where the backup agent is installed only on Hyper-V replica target host (no agent on source host).

After updating to Acronis Cyber Cloud v.8.0, you are getting the following alert from this plan triggered after some time:

Backup is missing: No successful backups for X days

Scheduled custom reports are not received

You have configured Scheduled Operations report on the Reports tab of the Management portal (Reports -> Operations).

Scheduled report is not received by any of the specified recipients.

Other notifications are working fine.

Data center is not available in 'Regional Acronis DC' list when activating SPLA


SPLA cannot be enabled due to limited list of Data Centers in Regional Acronis DC. Some of the DCs are missing in the list.


The list of available DCs will be updated in future releases. You can type your data center address manually, if it is not available in the list.

Log in as a Partner Admin, type in the DC address and activate the SPLA.

Changes in 'Items to back up' are not saved

You change Items to back up section of the backup plan: add or remove some of the protected items.

Changes are not saved.

Backup fails with "Windows error: (0x800705B4) This operation returned because the timeout period expired"


Activity fails with one of the following errors:

Windows error: (0x800705B4) This operation returned because the timeout period expired


Operating system error: This operation returned because the timeout period expired

Вackup fails with 'Common I/O error'

A Linux machine backup fails with this error message:

Message: Failed to create volume snapshot.
Error code: 5832705
Fields: {"$module":"disk_bundle_lxa64_15300","device":"/dev/md1"}
Message: Common I/O error.

You see these errors in /var/log/messages/
Jan  6 23:22:11 kernel: heartbeat_timer_func(swapper/0,0): Deadlock, cnt=6, state=4. Unfreezing...
Jan  6 23:22:11 kernel: find_deadlocked(snapapid,7404): dev=900001 state=1024
Jan  6 23:22:12 kernel: do_resolver(snapapid,7404): Real cleanup started... s=ffff9b7209fbc000(900001)
Jan  6 23:22:12 kernel: find_deadlocked(snapapid,7404): dev=900001 state=256
Jan  6 23:22:12 kernel: find_deadlocked(snapapid,7404): dev=900002 state=2


Most popular articles

Operation fails with "data is corrupted: CRC mismatch or internal data structures mismatch"


1.  Operation with a backup archive (backup, replication, validation, etc.) fails with the following message:

Data is corrupted: CRC mismatch or internal data structures mismatch

Backup fails with "VSS writer 'System Writer' with class ID 'E8132975-6F93-4464-A53E-1050253AE220' has timed out" error"

Backup fails with:

The backup has failed because 'VSS Writer' has timed out during snapshot creation



Windows error: (0x800423F2) VSS writer 'System Writer' with class ID 'E8132975-6F93-4464-A53E-1050253AE220' has timed out. This may be caused by too intensive I/O on the machine at the backup start time. Try to re-schedule the backup to some different time. To troubleshoot VSS issues, download and run Acronis VSS Doctor available at

Incomplete backups occupy space; how to delete

You start a backup plan for the first time. After the first backup has not completed (for any reason), you want to delete this incomplete archive, but cannot find it under Backups. Or you notice, that space used in Acronis Cloud is larger than your backups occupy.

"Failed to Connect to the Process" error

You may get the error as a result of exceeded timeout for disk system initialization. Disk system initialization is executed during backup. To fix it, add a value StartTimeout in Windows registry.

"The activity has failed due to a restart of the service" error

An operation in Acronis Backup 12.5 or Acronis Backup Cloud fails with "The activity has failed due to a restart of the service." or "The activity has failed due to an unexpected machine reboot or the backup process was terminated."

Machine is offline in Backup Management Console

After successful installation, the machine is offline in the Backup management console.

Backup finishes with warning "Creating a crash-consistent snapshot of virtual machine because the creation of its application-consistent snapshot has failed"

Backup of virtual machines finishes with warnings:

Creating a crash-consistent snapshot of virtual machine 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX' because the creation of its application-consistent snapshot has failed. Failed to create the virtual machine snapshot.

Manual registration fails with "Couldn't connect to host at localhost:43234" on Linux

You faced an issue with the registration of the Agent during the automatic installation and try to use the instruction from the article 55244:Acronis Backup Cloud: Registering Backup Client Manually

The RegisterAgent tool gives you an error:

| error 0x2260007: couldn't connect to host at localhost:43234
| line: 0xcbd08862963188d1
| file: e:/271/enterprise/common/http/curl_transport.cpp:284
| function: PerformRequest
| $module: register_agent_lxa64_10790

OR in Linux

The registration failed due to a problem on the Management Server. Either the backup service on this machine could not access the Management Server or the server returned an error response. Please make sure that the Management Server is accessible through the network and try again.

Backup to Acronis Cloud Storage fails with "Network disconnected by timeout"


Backup to Acronis Cloud fails with message:

Network disconnected by timeout

"VSS writer 'SqlServerWriter' with class ID 'A65FAA63-5EA8-4EBC-9DBD-A0C4DB26912A' has failed to process the snapshot"


Backup fails with the following message: