Failed to open the zip file when migrating from cloud to self-hosted

@amy.blais @agriesser

The date of cloud free depreciation is close, but we have got another problem of export:

ID: st9649igktb19ee6qqgwjoayjc
Status: error
Created: 2023-07-20 00:34:46 +0800 CST
Started: 2023-07-20 04:46:15 +0800 CST
Data: map[channels_exported:10 direct_channels_exported:46 direct_posts_exported:38750 error:Error during job execution. — exportFileAttachment: Failed to copy file during export., err=The specified key does not exist. include_attachments:true posts_exported:8566 teams_exported:1 users_exported:18]

I have tried several times but in vain…