OVERVIEW Sad experience - i lost my annotations for two chapters from a book. STEPS TO REPRODUCE i opened a book in okular and was adding annotations without intermediate save during several hours. When i wanted to close book and save it, got error message and empty file listing in directory about to save (this should be the hint) OBSERVED RESULT Error while trying to save document with added annotations to ".okular" archive. Error message: "Unable to create io-slave. Can not create socket for launching io-slave for protocol 'file'..." EXPECTED RESULT SOFTWARE/OS VERSIONS Linux/Ubuntu 18.04.2 LTS ADDITIONAL INFORMATION i understand this may be related to system side bug, when app is not able to list files in directory, but the app itself may resist in this scenario by knowing destination file path only