Failed to index guest file system. Failed to zip folder

Hello 🙂

My first guess if this is across multiple VMs is your anti-virus software is locking the zip file as it’s being created to scan it, so check your AV exclusions.

Hello @Nikks,
Do you have seen this article ?

https://forums.veeam.com/vmware-vsphere-f24/problems-with-guestindexdata-zip-t42132.html

...and Helpcenter: 

https://helpcenter.veeam.com/docs/backup/em/indexing_hiw.html?ver=120

Confirmed AV is not blocking 

Need to check the proxy side. Will change and see how it goes

No luck. I changed to local proxy from automatic , still same issue. This is happening to only a set of vms, others are working with same configuration with automatic proxy.

it is still unresolved, but i have The following errors in the log

Error (3) Failed to zip folder 'C:\Users\\AppData\Local\Temp\cf43f637-a10d-44a4-b090-18d395e73a9f' to file 'C:\Users\\AppData\Local\Temp\cf43f637-a10d-44a4-b090-18d395e73a9f\GuestIndexData.zip' (System.Exception)
[2024-06-17 20:17:29] <53> Error (3) at Veeam.Backup.Common.CZipArchiver.ZipFolder(String folderPath, String zipFilePath, Boolean deletePacked, String archiveInsideRootFolderPath, Action`1 saveProgressAction)
[2024-06-17 20:17:29] <53> Error (3) at Veeam.Backup.Core.CCatIndex.ArchiveAndCreate(String catIndexDirPath)
[2024-06-17 20:17:29] <53> Error (3) at Veeam.Backup.Core.CViGuestDiskIndexer.Veeam.Backup.Core.IGuestDiskIndexer.Index(String& outputDirPath)
[2024-06-17 20:17:29] <53> Error (3) at Veeam.Backup.Core.CViGuestCatIndexer.TryToIndex(Guid jobId, CCatIndex& catIndex, Boolean& isGuestGroupMembersAvailable, String& outputFolder)
[2024-06-17 20:17:29] <53> Error (3) Illegal characters in path. (System.ArgumentException)
[2024-06-17 20:17:29] <53> Error (3) at System.Security.Permissions.FileIOPermission.EmulateFileIOPermissionChecks(String fullPath)
[2024-06-17 20:17:29] <53> Error (3) at System.Security.Permissions.FileIOPermission.QuickDemand(FileIOPermissionAccess access, String fullPath, Boolean checkForDuplicates, Boolean needFullPath)
[2024-06-17 20:17:29] <53> Error (3) at System.IO.File.InternalGetLastWriteTimeUtc(String path, Boolean checkHost)
[2024-06-17 20:17:29] <53> Error (3) at Ionic.Zip.ZipEntry.Create(String nameInArchive, ZipEntrySource source, Object arg1, Object arg2)
[2024-06-17 20:17:29] <53> Error (3) at Ionic.Zip.ZipFile.AddFile(String fileName, String directoryPathInArchive)
[2024-06-17 20:17:29] <53> Error (3) at Veeam.Backup.Common.CZipArchiver.ZipFolderRecursively(ZipFile zip, String folderPath, String insideFolderPath)
[2024-06-17 20:17:29] <53> Error (3) at Veeam.Backup.Common.CZipArchiver.ZipFolder(String folderPath, String zipFilePath, Boolean deletePacked, String archiveInsideRootFolderPath, Action`1 saveProgressAction)

Any one know what is this Illegal characters in path error means?

Unsure what the illegal character is in the error as the path does not seem to have an illegal character.  I might suggest at this point to contact Support for further assistance as they will be able to dive deeper in to the log files to assist.  Keep us posted.