Periodically, we have a strange problem with our installation of 1.9.12.
Individual links to files suddenly behave as if the file is corrupt when accessed via a resource (such as SCORM module, video in mplayer, PDF resource). For example: A PDF will suddently act like a broken link and partially loads and hangs, a video will freeze on load or attempt to load infinitely, a SCORM module will stall at the start or part way through.
To solve this, we go into Files for the course (or into the folder on the server), rename the file (i.e. add V1, V2) and then change the resource to point to the renamed file. The file will then work correctly until this occurs again days, weeks or months later. There is nothing wrong with the file and the resource is still linked to exactly the same file only with a different name.
This is currently occurring with files across our site. It is very frustrating for users and time consuming for us. We thought it might be the antivirus software on the server and excluded moodledata from scanning, but this was not the cause.
Any thoughts or ideas appreciated.