From 35d6aad6cd7e8a16fbb829dcf8f0b70db12d0028 Mon Sep 17 00:00:00 2001
From: Remco Burema <r.burema@ultimaker.com>
Date: Thu, 28 Jan 2021 11:41:46 +0100
Subject: [PATCH] Small fix for slice before main window visible.

---
 plugins/CuraEngineBackend/CuraEngineBackend.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/plugins/CuraEngineBackend/CuraEngineBackend.py b/plugins/CuraEngineBackend/CuraEngineBackend.py
index eed9d56741..355406fe62 100755
--- a/plugins/CuraEngineBackend/CuraEngineBackend.py
+++ b/plugins/CuraEngineBackend/CuraEngineBackend.py
@@ -250,6 +250,9 @@ class CuraEngineBackend(QObject, Backend):
     @call_on_qt_thread  # must be called from the main thread because of OpenGL
     def _createSnapshot(self) -> None:
         self._snapshot = None
+        if not CuraApplication.getInstance().isVisible():
+            Logger.log("w", "Attempt to create snapshot before complete initialization.")
+            return
         Logger.log("i", "Creating thumbnail image (just before slice)...")
         try:
             self._snapshot = Snapshot.snapshot(width = 300, height = 300)