diff --git a/viewer/JFJochImageReadingWorker.cpp b/viewer/JFJochImageReadingWorker.cpp
index 08eb7ad7..6582700c 100644
--- a/viewer/JFJochImageReadingWorker.cpp
+++ b/viewer/JFJochImageReadingWorker.cpp
@@ -729,18 +729,31 @@ void JFJochImageReadingWorker::EnsurePixelRefine_i() {
         pixel_pred_ = CreateBraggPrediction(curr_experiment.IsRotationIndexing());
 }
 
-bool JFJochImageReadingWorker::BuildPixelSeed_i(PixelRefineData &d, const PixelRefineParams &p) const {
-    if (!current_image_ptr || !index_and_refine || !current_image.has_value())
+bool JFJochImageReadingWorker::BuildPixelSeed_i(PixelRefineData &d, const PixelRefineParams &p, QString &reason) const {
+    if (!current_image_ptr || !index_and_refine || !current_image.has_value()) {
+        reason = "No image loaded";
         return false;
+    }
 
     const auto &outcomes = index_and_refine->GetIntegrationOutcome();
     const int64_t n = current_image.value();
-    if (n < 0 || n >= static_cast<int64_t>(outcomes.size()))
+    if (n < 0 || n >= static_cast<int64_t>(outcomes.size())) {
+        reason = "No analysis result for current image";
         return false;
+    }
 
     const auto &io = outcomes[n];
-    if (io.reflections.empty()) // image not indexed/integrated
+    if (io.reflections.empty()) {
+        // The "indexed" badge in the viewer comes from indexing (lattice_type);
+        // PixelRefine instead seeds from the *integration* outcome, which is only
+        // populated when Quick integration is enabled and succeeds for this image.
+        // Distinguish the two so the user knows what to turn on.
+        if (current_image_ptr->ImageData().lattice_type.has_value())
+            reason = "Image is indexed but not integrated - enable Quick integration";
+        else
+            reason = "Current image is not indexed";
         return false;
+    }
 
     d.geom = io.geom;
     d.latt = io.latt;
@@ -773,7 +786,15 @@ bool JFJochImageReadingWorker::BuildPixelSeed_i(PixelRefineData &d, const PixelR
 
 std::shared_ptr<SimpleImage> JFJochImageReadingWorker::WrapFloatImage_i(const std::vector<float> &img) const {
     auto si = std::make_shared<SimpleImage>();
-    si->image = CompressedImage(img, curr_experiment.GetXPixelsNum(), curr_experiment.GetYPixelsNum());
+    // CompressedImage is a non-owning view over its data pointer. predictedImageReady
+    // is a queued cross-thread connection, so the source float vector must outlive the
+    // emit: copy it into SimpleImage::buffer (which the shared_ptr keeps alive) instead
+    // of aliasing the caller's temporary, otherwise loadImageInternal() reads freed
+    // memory in the GUI thread (SIGSEGV).
+    si->buffer.resize(img.size() * sizeof(float));
+    std::memcpy(si->buffer.data(), img.data(), si->buffer.size());
+    si->image = CompressedImage(si->buffer, curr_experiment.GetXPixelsNum(), curr_experiment.GetYPixelsNum(),
+                                CompressedImageMode::Float32);
     return si;
 }
 
@@ -803,8 +824,9 @@ void JFJochImageReadingWorker::PixelRefinePreview(PixelRefineParams params) {
     }
 
     PixelRefineData d;
-    if (!BuildPixelSeed_i(d, params)) {
-        emit pixelRefineStatus("Current image is not indexed");
+    QString seed_reason;
+    if (!BuildPixelSeed_i(d, params, seed_reason)) {
+        emit pixelRefineStatus(seed_reason);
         return;
     }
 
@@ -838,8 +860,9 @@ void JFJochImageReadingWorker::PixelRefineRun(PixelRefineParams params) {
     }
 
     PixelRefineData d;
-    if (!BuildPixelSeed_i(d, params)) {
-        emit pixelRefineStatus("Current image is not indexed");
+    QString seed_reason;
+    if (!BuildPixelSeed_i(d, params, seed_reason)) {
+        emit pixelRefineStatus(seed_reason);
         return;
     }
     if (d.max_iterations <= 0)
diff --git a/viewer/JFJochImageReadingWorker.h b/viewer/JFJochImageReadingWorker.h
index a5b219df..93d4240b 100644
--- a/viewer/JFJochImageReadingWorker.h
+++ b/viewer/JFJochImageReadingWorker.h
@@ -69,7 +69,7 @@ private:
     std::unique_ptr<BraggPrediction> pixel_pred_;
 
     void EnsurePixelRefine_i();
-    bool BuildPixelSeed_i(PixelRefineData &d, const PixelRefineParams &p) const;
+    bool BuildPixelSeed_i(PixelRefineData &d, const PixelRefineParams &p, QString &reason) const;
     std::shared_ptr<SimpleImage> WrapFloatImage_i(const std::vector<float> &img) const;
 
     std::unique_ptr<ROIElement> roi;
diff --git a/viewer/windows/JFJochPixelRefineWindow.cpp b/viewer/windows/JFJochPixelRefineWindow.cpp
index 6cce6a99..bd4e1927 100644
--- a/viewer/windows/JFJochPixelRefineWindow.cpp
+++ b/viewer/windows/JFJochPixelRefineWindow.cpp
@@ -145,16 +145,26 @@ void JFJochPixelRefineWindow::onControlChanged() {
 }
 
 void JFJochPixelRefineWindow::imageLoaded(std::shared_ptr<const JFJochReaderImage> image) {
-    if (m_beamInit || !image)
+    if (!image)
         return;
-    const auto geom = image->Dataset().experiment.GetDiffractionGeometry();
-    m_beamx->setMax(static_cast<double>(image->Dataset().experiment.GetXPixelsNum()));
-    m_beamy->setMax(static_cast<double>(image->Dataset().experiment.GetYPixelsNum()));
-    m_suppress = true;
-    m_beamx->setValue(geom.GetBeamX_pxl());
-    m_beamy->setValue(geom.GetBeamY_pxl());
-    m_suppress = false;
-    m_beamInit = true;
+
+    // Initialise the beam-centre sliders from the geometry once.
+    if (!m_beamInit) {
+        const auto geom = image->Dataset().experiment.GetDiffractionGeometry();
+        m_beamx->setMax(static_cast<double>(image->Dataset().experiment.GetXPixelsNum()));
+        m_beamy->setMax(static_cast<double>(image->Dataset().experiment.GetYPixelsNum()));
+        m_suppress = true;
+        m_beamx->setValue(geom.GetBeamX_pxl());
+        m_beamy->setValue(geom.GetBeamY_pxl());
+        m_suppress = false;
+        m_beamInit = true;
+    }
+
+    // Request a predicted-image preview for the (re)loaded image. Without this the
+    // preview only refreshed on a slider change, so opening/reanalyzing an image
+    // left the predicted view empty. The worker no-ops if there is no reference or
+    // the image is not integrated yet.
+    onControlChanged();
 }
 
 void JFJochPixelRefineWindow::setPredictedImage(std::shared_ptr<const SimpleImage> image) {