diff --git a/application/lib/calibre/ebooks/conversion/plugins/recipe_input.py b/application/lib/calibre/ebooks/conversion/plugins/recipe_input.py
index e5b34537..c56bc2cc 100644
--- a/application/lib/calibre/ebooks/conversion/plugins/recipe_input.py
+++ b/application/lib/calibre/ebooks/conversion/plugins/recipe_input.py
@@ -295,7 +295,7 @@ def build_meta(self, recipe1, onlyRecipe):
         try:
             pdate = recipe1.publication_date()
         except Exception as e:
-            default_log.warning('recipe1.publication_date error: {e}')
+            default_log.warning(f'recipe1.publication_date error: {e}')
             pdate = self.user.local_time()
         timefmt = recipe1.timefmt.strip()
         if timefmt and self.user.book_cfg('title_fmt'):
diff --git a/application/lib/calibre/ebooks/conversion/plumber.py b/application/lib/calibre/ebooks/conversion/plumber.py
index 37221c57..15a3eb1e 100644
--- a/application/lib/calibre/ebooks/conversion/plumber.py
+++ b/application/lib/calibre/ebooks/conversion/plumber.py
@@ -396,8 +396,10 @@ def run(self):
         try:
             self.oeb = self.input_plugin(self.input_, self.opts, self.input_fmt, self.log, tdir, fs)
         except Exception as e:
-            #self.log.warning('Failed to execute input plugin: {}'.format(str(e)))
-            self.log.warning('Failed to execute input plugin: {}'.format(traceback.format_exc()))
+            if 'All feeds are empty, aborting.' in str(e):
+                self.log.warning('Failed to execute input plugin: {}'.format(str(e)))
+            else:
+                self.log.warning('Failed to execute input plugin: {}'.format(traceback.format_exc()))
             fs.clear()
             return
 
diff --git a/worker.yaml b/worker.yaml
index ee5fbde3..cb068cbd 100644
--- a/worker.yaml
+++ b/worker.yaml
@@ -7,7 +7,7 @@ service: worker
 #B4: 1536MB/2.4GHz/manual_scaling
 #B4_1G: 3072MB/2.4GHz/manual_scaling
 #B8: 3072MB/4.8GHz/manual_scaling
-instance_class: B4
+instance_class: B2
 basic_scaling:
   max_instances: 2
   idle_timeout: 30m