diff --git a/docling/models/readingorder_model.py b/docling/models/readingorder_model.py
index ba1bb45..9c38756 100644
--- a/docling/models/readingorder_model.py
+++ b/docling/models/readingorder_model.py
@@ -124,7 +124,7 @@ class ReadingOrderModel:
             page_no = page.page_no + 1
             size = page.size
 
-            assert size is not None
+            assert size is not None, "Page size is not initialized."
 
             out_doc.add_page(page_no=page_no, size=size)
 
diff --git a/docling/pipeline/base_pipeline.py b/docling/pipeline/base_pipeline.py
index 29475d6..2b16810 100644
--- a/docling/pipeline/base_pipeline.py
+++ b/docling/pipeline/base_pipeline.py
@@ -193,6 +193,17 @@ class PaginatedPipeline(BasePipeline):  # TODO this is a bad name.
                 )
                 raise e
 
+            # Filter out uninitialized pages (those with size=None) that may remain
+            # after timeout or processing failures to prevent assertion errors downstream
+            initial_page_count = len(conv_res.pages)
+            conv_res.pages = [page for page in conv_res.pages if page.size is not None]
+
+            if len(conv_res.pages) < initial_page_count:
+                _log.info(
+                    f"Filtered out {initial_page_count - len(conv_res.pages)} uninitialized pages "
+                    f"due to timeout or processing failures"
+                )
+
         return conv_res
 
     def _unload(self, conv_res: ConversionResult) -> ConversionResult: