Can not save the source file

Hello, when I open up my Pharo6.0 image and left+click > save as... to save my image, Pharo tells me that it could no save the source file. Unfortunately the message disappears too fast, so I can not paste it here ;-) I've checked the Pharo version I've downloaded and the sources-file is present: # ls -l shared drwxrwxr-x 2 marc marc 4096 Jun 9 14:40 icon-packs -rw-r--r-- 1 marc marc 1361267 Jun 9 15:48 Pharo6.0.changes -rw-r--r-- 1 marc marc 36798736 Jun 6 15:24 Pharo6.0.image -rw-rw-r-- 1 marc marc 43775 Jun 9 15:47 PharoDebug.log drwxrwxr-x 6 marc marc 4096 Jun 8 15:21 pharo-local -rw-r--r-- 1 marc marc 36114887 Jun 6 15:24 PharoV60.sources Any hints what I'm missing? Best regards, Marc