1-800-691-1991 | 9am - 8pm ET

Veeam Backup for Microsoft Office 365 4c cumulative patch KB3222

KB ID: 3222
Product: Veeam Backup for Microsoft Office 365
Version: 4c
Published: 2020-07-09
Last Modified: 2021-02-16


Please confirm you are running Veeam Backup for Microsoft Office 365 build prior to installing this cumulative patch KB3222. You can check this under Help > About in Veeam Backup for Microsoft Office 365 console. After upgrading, your build version will change to

As a result of on-going R&D effort and in response to customer feedback, cumulative patch KB3222 provides a set of enhancements and bug fixes, the most significant of which are listed below:


  • Optimized reading from object storage repository to reduce the cost of querying the first 100 items in a folder when exploring backups with Veeam Explorers.
  • Parallel processing of requests for obtaining used space in backup repositories initiated via PowerShell or REST API on multiple proxies.
  • Reduced backup times to object storage repositories targets when processing SharePoint and OneDrive for Business items with thousands of versions.

Resolved Issues

  • After updating to Veeam Backup for Microsoft Office 365 4c (build backups start to fail with the “Proxy offline time exceeded” error. For more details, see KB3216.
  • Under certain conditions, the backup proxy server sends ‘Success’ notifications about backup job completion results for backup jobs failed with the “Proxy offline time exceeded” error.
  • Unable to update certificate information for S3 Compatible object storage after the trusted certificate has been changed and a backup repository extended to such object storage goes to the ‘Invalid’ state.
  • OneDrive restore in the Modern Authentication mode fails with the “Cannot connect to Office 365” error.
  • Backup job initiated with the /v4/Jobs/{backup_job_id}/action REST API request performs full backup sync instead of incremental sync.
  • In the UI, changes to the schedule of applying retention policy settings for existing backup repositories are not saved.
  • SharePoint backup fails with the “The Attachments column does not exist. It may have been removed by another user” error.
  • Under certain conditions, in the Modern Authentication mode with legacy protocols enabled, Public Folder mailbox backup fails with the “Too many concurrent connections opened. Cannot open mailbox” error.
KB ID: 3222
Product: Veeam Backup for Microsoft Office 365
Version: 4c
Published: 2020-07-09
Last Modified: 2021-02-16

Couldn't find what you were looking for?

Below you can submit an idea for a new knowledge base article.
Report a typo on this page:

Please select a spelling error or a typo on this page with your mouse and press CTRL + Enter to report this mistake to us. Thank you!

Spelling error in text

Knowledge base content request
By submitting, you agree that your personal data will be managed by Veeam in accordance with the Privacy Policy.

ty icon

Thank you!

We have received your request and our team will reach out to you shortly.


error icon

Oops! Something went wrong.

Please go back try again later.