diff --git a/trains/backend_interface/metrics/events.py b/trains/backend_interface/metrics/events.py
index 6997bd5e..43ef4f8a 100644
--- a/trains/backend_interface/metrics/events.py
+++ b/trains/backend_interface/metrics/events.py
@@ -183,7 +183,9 @@ class UploadEvent(MetricsEventAdapter):
 
     @staticmethod
     def _replace_slash(part):
-        return part.replace('\\', '/').strip('/').replace('/', '.slash.')
+        # replace the three quote symbols we cannot have,
+        # notice % will be converted to %25 when the link is quoted, so we should not use it
+        return part.replace('\\', '/').strip('/').replace('/', '.slash.').replace('?', '0x3F').replace('#', '0x23')
 
     def __init__(self, metric, variant, image_data, local_image_path=None, iter=0, upload_uri=None,
                  file_history_size=None, delete_after_upload=False, **kwargs):