diff --git a/.DS_Store b/.DS_Store
index 4fd8f63..f98d79b 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/README.md b/README.md
index e86dcfc..eeabc7e 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,8 @@ $ sudo docker-compose pull
 $ sudo docker-compose up -d
 ```
 
+Tried to update to 1.39 from 1.35.5 did not work. Maybe a step by step update is needed now from 1.35.9
+
 ## Update of Plugins
 
 This is in the best case done with composer.
diff --git a/example.LocalSettings.php b/example.LocalSettings.php
index dc76a88..9f629fe 100644
--- a/example.LocalSettings.php
+++ b/example.LocalSettings.php
@@ -332,6 +332,11 @@ $wgPdftoText = '/usr/bin/pdftotext';
 $wgAllowExternalImages = true;
 $wgAllowExternalImagesFrom = [ 'http://127.0.0.1/', 'https://cloud.rd13server.de/' ]; // MediaWiki 1.14+
 
+# Extend preview creation file size and pixel size
+# Maximum amount of virtual memory available to shell processes under Linux, in KiB.
+$wgMaxShellMemory = 307200;
+$wgMaxShellFileSize = 307200;
+
 # Support Video Files and external Video Sources
 ################################################
 wfLoadExtension( 'EmbedVideo' );