diff --git a/sanofi/dist/etc/sanofi-dropbox/dropbox-all-in-one-with-library.py b/sanofi/dist/etc/sanofi-dropbox/dropbox-all-in-one-with-library.py
index a81791dc72f140192ebf2abe38838a012c0bd9fa..0bb260881fa7ff91f33f7ee31281f82616ea5864 100644
--- a/sanofi/dist/etc/sanofi-dropbox/dropbox-all-in-one-with-library.py
+++ b/sanofi/dist/etc/sanofi-dropbox/dropbox-all-in-one-with-library.py
@@ -246,8 +246,8 @@ def convertToPng(dir, transparentColor):
     machineLoad = ALLOWED_MACHINE_LOAD_DURING_THUMBNAIL_GENERATION
     maxThreads = 100
     errorMsg = FileConverter.performConversion(File(dir), strategy, machineLoad, maxThreads)
-    if errorMsg != None:
-        raise RuntimeException("Error converting overlays:", errorMsg)
+    if errorMsg:
+        raise RuntimeException("Error converting overlays:" + errorMsg)
 
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