diff --git a/app/MindWork AI Studio/Assistants/I18N/allTexts.lua b/app/MindWork AI Studio/Assistants/I18N/allTexts.lua
index c5e9e5c3..ba4ce53d 100644
--- a/app/MindWork AI Studio/Assistants/I18N/allTexts.lua	
+++ b/app/MindWork AI Studio/Assistants/I18N/allTexts.lua	
@@ -2410,6 +2410,9 @@ UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::
 -- Creates a new version from the current sources and instructions while keeping the current structure and design.
 UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::T2703645157"] = "Creates a new version from the current sources and instructions while keeping the current structure and design."
 
+-- Images are not supported by the selected provider and model. Select a model with image support, or remove the image sources.
+UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::T2720475627"] = "Images are not supported by the selected provider and model. Select a model with image support, or remove the image sources."
+
 -- Import as copy
 UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::T2745663129"] = "Import as copy"
 
diff --git a/app/MindWork AI Studio/Assistants/VisualBriefing/VisualBriefingAssistant.razor.Validation.cs b/app/MindWork AI Studio/Assistants/VisualBriefing/VisualBriefingAssistant.razor.Validation.cs
index aad36754..0c4f5a8d 100644
--- a/app/MindWork AI Studio/Assistants/VisualBriefing/VisualBriefingAssistant.razor.Validation.cs	
+++ b/app/MindWork AI Studio/Assistants/VisualBriefing/VisualBriefingAssistant.razor.Validation.cs	
@@ -1,4 +1,6 @@
 using AIStudio.Provider;
+using AIStudio.Settings;
+using AIStudio.Tools.Rust;
 
 using ProviderSettings = AIStudio.Settings.Provider;
 
@@ -15,6 +17,15 @@ public partial class VisualBriefingAssistant
     /// </remarks>
     private bool HasSourceMaterial => this.selectedBriefing?.Sources.Any(source => source.Kind is VisualBriefingSourceKind.SOURCE_MATERIAL) == true;
 
+    /// <summary>Gets whether any stored source reaches the model as an image.</summary>
+    /// <remarks>
+    /// Both source kinds can end up as an image: source preparation converts every visual asset into an
+    /// image attachment, and a source material file is attached as it is, where the attachment type is
+    /// derived from the file extension alone. Checking the extension therefore covers both, and it
+    /// matches the rule the attachment control already applies while a file is being added.
+    /// </remarks>
+    private bool HasImageSources => this.selectedBriefing?.Sources.Any(source => FileTypes.IsAllowedPath(source.Path, FileTypes.IMAGE)) == true;
+
     /// <summary>Gets all current field, source, and revision issues shown below the actions.</summary>
     /// <remarks>
     /// This is the complete list for the user. The generate buttons disable themselves from the same
@@ -53,6 +64,12 @@ public partial class VisualBriefingAssistant
     }
 
     /// <summary>Gets the issues with the stored sources, which block only the modes that read them.</summary>
+    /// <remarks>
+    /// The image check belongs here rather than to the fields, even though it depends on the selected
+    /// model: it only matters for the modes that hand the sources to the model at all. Changing just the
+    /// design reuses the stored evidence and sends no attachments, which is the same distinction the
+    /// build orchestrator makes before it runs source preparation.
+    /// </remarks>
     private IReadOnlyList<string> SourceIssues
     {
         get
@@ -64,6 +81,11 @@ public partial class VisualBriefingAssistant
             if (!this.HasSourceMaterial)
                 issues.Add(T("Please add at least one source material file."));
 
+            // A model can be selected long after the images were attached, so the capability that was
+            // checked while attaching them has to be checked again here:
+            if (this.HasImageSources && this.editor.Provider != ProviderSettings.NONE && !this.editor.Provider.SupportsImageInput())
+                issues.Add(T("Images are not supported by the selected provider and model. Select a model with image support, or remove the image sources."));
+
             foreach (var source in this.selectedBriefing.Sources)
             {
                 var fileName = Path.GetFileName(source.Path);
diff --git a/app/MindWork AI Studio/Plugins/languages/de-de-43065dbc-78d0-45b7-92be-f14c2926e2dc/plugin.lua b/app/MindWork AI Studio/Plugins/languages/de-de-43065dbc-78d0-45b7-92be-f14c2926e2dc/plugin.lua
index 87536244..53b1f26e 100644
--- a/app/MindWork AI Studio/Plugins/languages/de-de-43065dbc-78d0-45b7-92be-f14c2926e2dc/plugin.lua	
+++ b/app/MindWork AI Studio/Plugins/languages/de-de-43065dbc-78d0-45b7-92be-f14c2926e2dc/plugin.lua	
@@ -2412,6 +2412,9 @@ UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::
 -- Creates a new version from the current sources and instructions while keeping the current structure and design.
 UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::T2703645157"] = "Erstellt eine neue Version aus dem aktuellen Ausgangsmaterial und Anweisungen, wobei die bestehende Struktur und das Design beibehalten werden."
 
+-- Images are not supported by the selected provider and model. Select a model with image support, or remove the image sources.
+UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::T2720475627"] = "Bilder werden vom ausgewählten Anbieter und Modell nicht unterstützt. Wählen Sie ein Modell mit Bildunterstützung aus oder entfernen Sie die Bildquellen."
+
 -- Import as copy
 UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::T2745663129"] = "Als Kopie importieren"
 
diff --git a/app/MindWork AI Studio/Plugins/languages/en-us-97dfb1ba-50c4-4440-8dfa-6575daf543c8/plugin.lua b/app/MindWork AI Studio/Plugins/languages/en-us-97dfb1ba-50c4-4440-8dfa-6575daf543c8/plugin.lua
index ebd90710..b269603a 100644
--- a/app/MindWork AI Studio/Plugins/languages/en-us-97dfb1ba-50c4-4440-8dfa-6575daf543c8/plugin.lua	
+++ b/app/MindWork AI Studio/Plugins/languages/en-us-97dfb1ba-50c4-4440-8dfa-6575daf543c8/plugin.lua	
@@ -2412,6 +2412,9 @@ UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::
 -- Creates a new version from the current sources and instructions while keeping the current structure and design.
 UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::T2703645157"] = "Creates a new version from the current sources and instructions while keeping the current structure and design."
 
+-- Images are not supported by the selected provider and model. Select a model with image support, or remove the image sources.
+UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::T2720475627"] = "Images are not supported by the selected provider and model. Select a model with image support, or remove the image sources."
+
 -- Import as copy
 UI_TEXT_CONTENT["AISTUDIO::ASSISTANTS::VISUALBRIEFING::VISUALBRIEFINGASSISTANT::T2745663129"] = "Import as copy"
 
diff --git a/app/MindWork AI Studio/Settings/ProviderExtensions.cs b/app/MindWork AI Studio/Settings/ProviderExtensions.cs
index c1aa43b3..3d18e586 100644
--- a/app/MindWork AI Studio/Settings/ProviderExtensions.cs	
+++ b/app/MindWork AI Studio/Settings/ProviderExtensions.cs	
@@ -15,6 +15,23 @@ public static partial class ProviderExtensions
         return provider.CapabilityOverrides?.ApplyTo(automaticCapabilities) ?? automaticCapabilities;
     }
     
+    /// <summary>
+    /// Get whether the model used by the configured provider accepts images as input.
+    /// </summary>
+    /// <remarks>
+    /// Two capabilities express image input, one for a single image and one for several. Anything that
+    /// wants to know whether an image may be sent has to accept both, which is why the question is asked
+    /// here instead of at each call site: attaching a file and validating an already attached file must
+    /// never disagree about it.
+    /// </remarks>
+    /// <param name="provider">The configured provider.</param>
+    /// <returns><c>true</c> when the model accepts image input.</returns>
+    public static bool SupportsImageInput(this Provider provider)
+    {
+        var capabilities = provider.GetModelCapabilities();
+        return capabilities.Contains(Capability.SINGLE_IMAGE_INPUT) || capabilities.Contains(Capability.MULTIPLE_IMAGE_INPUT);
+    }
+
     /// <summary>
     /// Get the capabilities of a model for a specific provider.
     /// </summary>
diff --git a/app/MindWork AI Studio/Tools/Validation/FileExtensionValidation.cs b/app/MindWork AI Studio/Tools/Validation/FileExtensionValidation.cs
index 2251ecd5..3ac4ade6 100644
--- a/app/MindWork AI Studio/Tools/Validation/FileExtensionValidation.cs	
+++ b/app/MindWork AI Studio/Tools/Validation/FileExtensionValidation.cs	
@@ -1,4 +1,3 @@
-using AIStudio.Provider;
 using AIStudio.Settings;
 using AIStudio.Tools.PluginSystem;
 using AIStudio.Tools.Rust;
@@ -59,7 +58,6 @@ public static class FileExtensionValidation
             return false;
         }
 
-        var capabilities = provider?.GetModelCapabilities() ?? new();
         if (FileTypes.IsAllowedPath(filePath, FileTypes.IMAGE))
         {
             switch (useCae)
@@ -76,8 +74,7 @@ public static class FileExtensionValidation
                     return true;
                 
                 // In this use case, we can check the provider capabilities:
-                case UseCase.ATTACHING_CONTENT when capabilities.Contains(Capability.SINGLE_IMAGE_INPUT) ||
-                                                    capabilities.Contains(Capability.MULTIPLE_IMAGE_INPUT):
+                case UseCase.ATTACHING_CONTENT when provider?.SupportsImageInput() is true:
                     return true;
                 
                 // We know that images are not supported: