New DICOM refused since Azure plugin enabled

Hello,

Since activating the Azure Blob plugin, we’ve had some studies that refuse to register on the server.
I didn’t understand the exact reason, given that we’re in Hybrid mode with ‘WriteToFileSystem’ :

{
    "AzureBlobStorage": {
        "ConnectionString": "#####",
        "ContainerName": "#####",
        "CreateContainerIfNotExists": false,
        "RootPath": "",
        "MigrationFromFileSystemEnabled": false,
        "StorageStructure": "flat",
        "StorageEncryption": {
            "Enable": false
        },
        "HybridMode": "WriteToFileSystem"
    }
}

It try to delete some .dcm files that doesn’t exists in the blob Azure.

Deactivating the plugin no longer poses any problems for image reception in particular.
This is a new study that didn’t exist on the server before.

Here are the server error messages :

W0717 11:44:22.447568             MAIN main.cpp:2103] Orthanc version: 1.12.8
I0717 11:44:22.447568             MAIN main.cpp:2135] Architecture: 64-bit, little endian
W0717 11:44:22.811402             MAIN PluginsManager.cpp:158] Azure Blob Storage plugin is initializing
W0717 11:44:22.811402             MAIN PluginsManager.cpp:158] Azure Blob Storage: WriteToFileSystem HybridMode is enabled: writing to file system, try reading first from file system and, then, from object-storage
W0717 11:44:22.811402             MAIN PluginsManager.cpp:158] Azure Blob Storage: HybridMode: reading from file system is enabled, source: D:\Orthanc
I0717 11:44:22.811402             MAIN PluginsManager.cpp:162] (plugins) Connecting to Azure storage ...
I0717 11:44:22.811402             MAIN PluginsManager.cpp:162] (plugins) Blob client created
I0717 11:44:22.811402             MAIN PluginsManager.cpp:162] (plugins) Blob storage initialized
W0717 11:44:22.811402             MAIN PluginsManager.cpp:158] Azure Blob Storage: client-side encryption is disabled
I0717 11:44:25.781011  DB HOUSEKEEPING postgresql-index:/PostgreSQLIndex.cpp:810] No missing ChildCount entries
I0717 11:44:44.513325     DICOM-SERVER CommandDispatcher.cpp:334] (dicom) Association Received from AET  on IP 192.168.1.20
I0717 11:44:44.513325     DICOM-SERVER CommandDispatcher.cpp:385] (dicom) No presentation context proposed
I0717 11:44:44.513325     DICOM-SERVER CommandDispatcher.cpp:334] (dicom) Association Received from AET MODAL1 on IP 192.168.1.20
I0717 11:44:44.513325     DICOM-SERVER main.cpp:324] Incoming connection from AET MODAL1 on IP 192.168.1.20, calling AET ORTHANC
I0717 11:44:44.513325     DICOM-SERVER CommandDispatcher.cpp:675] (dicom) Association Acknowledged (Max Send PDV: 131060) to AET MODAL1 on IP 192.168.1.20
I0717 11:44:44.585862          DICOM-1 main.cpp:359] Incoming Store request from AET MODAL1 on IP 192.168.1.20, calling AET ORTHANC
I0717 11:44:44.602050     DICOM-SERVER CommandDispatcher.cpp:334] (dicom) Association Received from AET  on IP 192.168.1.20
I0717 11:44:44.602050     DICOM-SERVER CommandDispatcher.cpp:385] (dicom) No presentation context proposed
I0717 11:44:44.602050          DICOM-1 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): creating attachment 3703cee4-4f37-4cc0-8ab4-423dfac664cd of type 1
I0717 11:44:44.602050     DICOM-SERVER CommandDispatcher.cpp:334] (dicom) Association Received from AET MODAL1 on IP 192.168.1.20
I0717 11:44:44.602050     DICOM-SERVER main.cpp:324] Incoming connection from AET MODAL1 on IP 192.168.1.20, calling AET ORTHANC
I0717 11:44:44.602050     DICOM-SERVER CommandDispatcher.cpp:675] (dicom) Association Acknowledged (Max Send PDV: 131060) to AET MODAL1 on IP 192.168.1.20
I0717 11:44:44.602050          DICOM-2 main.cpp:359] Incoming Store request from AET MODAL1 on IP 192.168.1.20, calling AET ORTHANC
I0717 11:44:44.602050          DICOM-2 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): creating attachment 7a3e4a9e-1ab8-42f8-9a70-55e863015030 of type 1
I0717 11:44:44.617688     DICOM-SERVER CommandDispatcher.cpp:334] (dicom) Association Received from AET  on IP 192.168.1.20
I0717 11:44:44.617688     DICOM-SERVER CommandDispatcher.cpp:385] (dicom) No presentation context proposed
I0717 11:44:44.633313     DICOM-SERVER CommandDispatcher.cpp:334] (dicom) Association Received from AET MODAL1 on IP 192.168.1.20
I0717 11:44:44.633313     DICOM-SERVER main.cpp:324] Incoming connection from AET MODAL1 on IP 192.168.1.20, calling AET ORTHANC
I0717 11:44:44.633313     DICOM-SERVER CommandDispatcher.cpp:675] (dicom) Association Acknowledged (Max Send PDV: 131060) to AET MODAL1 on IP 192.168.1.20
I0717 11:44:44.633313          DICOM-3 main.cpp:359] Incoming Store request from AET MODAL1 on IP 192.168.1.20, calling AET ORTHANC
I0717 11:44:44.633313     DICOM-SERVER CommandDispatcher.cpp:334] (dicom) Association Received from AET  on IP 192.168.1.20
I0717 11:44:44.633313     DICOM-SERVER CommandDispatcher.cpp:385] (dicom) No presentation context proposed
I0717 11:44:44.633313     DICOM-SERVER CommandDispatcher.cpp:334] (dicom) Association Received from AET MODAL1 on IP 192.168.1.20
I0717 11:44:44.633313     DICOM-SERVER main.cpp:324] Incoming connection from AET MODAL1 on IP 192.168.1.20, calling AET ORTHANC
I0717 11:44:44.633313     DICOM-SERVER CommandDispatcher.cpp:675] (dicom) Association Acknowledged (Max Send PDV: 131060) to AET MODAL1 on IP 192.168.1.20
I0717 11:44:44.633313          DICOM-3 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): creating attachment c4cb443a-30b5-4ea5-9a36-bb76768bd6db of type 1
I0717 11:44:44.633313          DICOM-0 main.cpp:359] Incoming Store request from AET MODAL1 on IP 192.168.1.20, calling AET ORTHANC
I0717 11:44:44.633313          DICOM-0 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): creating attachment 88db3713-9f6f-464e-9d53-c3b356b63a20 of type 1
I0717 11:44:44.648943          DICOM-2 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): created attachment 7a3e4a9e-1ab8-42f8-9a70-55e863015030 (162.89KB in 46.89ms = 28.46Mbps)
I0717 11:44:44.664568          DICOM-1 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): created attachment 3703cee4-4f37-4cc0-8ab4-423dfac664cd (164.64KB in 62.52ms = 21.57Mbps)
I0717 11:44:44.700855          DICOM-2 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): deleting attachment 7a3e4a9e-1ab8-42f8-9a70-55e863015030 of type 1
I0717 11:44:44.700855          DICOM-2 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Secondary: object-storage): deleting attachment 7a3e4a9e-1ab8-42f8-9a70-55e863015030 of type 1
I0717 11:44:44.726004          DICOM-1 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): deleting attachment 3703cee4-4f37-4cc0-8ab4-423dfac664cd of type 1
I0717 11:44:44.726004          DICOM-1 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Secondary: object-storage): deleting attachment 3703cee4-4f37-4cc0-8ab4-423dfac664cd of type 1
I0717 11:44:44.726004          DICOM-3 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): created attachment c4cb443a-30b5-4ea5-9a36-bb76768bd6db (161.38KB in 92.69ms = 14.26Mbps)
I0717 11:44:44.741703          DICOM-3 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Primary: file-system): deleting attachment c4cb443a-30b5-4ea5-9a36-bb76768bd6db of type 1
I0717 11:44:44.741703          DICOM-3 PluginsManager.cpp:162] (plugins) Azure Blob Storage (Secondary: object-storage): deleting attachment c4cb443a-30b5-4ea5-9a36-bb76768bd6db of type 1
E0717 11:44:44.783025          DICOM-2 PluginsManager.cpp:154] Azure Blob Storage: error while deleting object 7a3e4a9e-1ab8-42f8-9a70-55e863015030: AzureBlobStorage: error while deleting file 7a3e4a9e-1ab8-42f8-9a70-55e863015030.dcm: 404 The specified blob does not exist.
The specified blob does not exist.
RequestId:7b4a8cf0-f01e-00f8-3dff-f69f13000000
Time:2025-07-17T09:44:44.7806943Z
Request ID: 7b4a8cf0-f01e-00f8-3dff-f69f13000000
E0717 11:44:44.783025          DICOM-2 StoreScp.cpp:199] Exception while storing DICOM: Error in the plugin implementing a custom storage area
I0717 11:44:44.783025          DICOM-2 main.cpp:359] Incoming Store request from AET MODAL1 on IP 192.168.1.20, calling AET ORTHANC
E0717 11:44:44.783025          DICOM-1 PluginsManager.cpp:154] Azure Blob Storage: error while deleting object 3703cee4-4f37-4cc0-8ab4-423dfac664cd: AzureBlobStorage: error while deleting file 3703cee4-4f37-4cc0-8ab4-423dfac664cd.dcm: 404 The specified blob does not exist.

With the plugin active, I have no problem reading an image on blob storage.
In case you have any idea what’s going on.

Thanks in advance.

Chris.