server‑side AzCopy transfers consistently failing with 403 AuthorizationFailure

[m-eshtiaghy]

The issue involves server‑side AzCopy transfers consistently failing with 403 AuthorizationFailure when attempting to write to the destination Azure Blob Storage. All GET operations succeed without issue, but every PUT request fails immediately during block commit. This behavior persists even when using SAS tokens that explicitly include full permissions (Read, Add, Create, Write, Delete, List) in destination storage account and the correct resource types (Service, Container, Object).
The source storage account is located in another tenant, and the operator is accessing the destination tenant using a guest account. Multiple SAS tokens (UDSAS and Account SAS) were generated and validated, but the destination storage account continues rejecting write operations while still allowing reads and listings.
As an additional verification step, Azure Storage Explorer was used to manually copy/paste files into the same destination container. This operation also fails, returning the error:

{
"name": null,
"message": ""UnexpectedCancel""
}

[craxal]

@m-eshtiaghy This repo is for issues related to Storage Explorer, but is sounds like you are reporting an issue with AzCopy itself. Is that correct? If so, this issue should be transferred to AzCopy.

[m-eshtiaghy]

Hey Craxal,

Actually the issue reported is happening in both environment with same error, so please you consider the issue in Azure storage explorer.

[craxal]

@m-eshtiaghy I'm sorry, I think I misinterpreted "server-side". You mean that you tried to start a copy from one account in one tenant to another account in another tenant, right? I think we found a small logic error in the code that could be causing this.

In the meantime, can you share the AzCopy command that Storage Explorer used for your transfer? Can you also share your applicationa and AzCopy logs?

For the copy within the same container, is the error that occurred the same as the cross-tenant error? Did you try to copy the item to a different folder or the same folder? If this is a concern, please share your AzCopy command for this operation as well.