Add 'General problems' paragraph

README.md

@@ -463,6 +463,12 @@ But that's the price of starting playback fast.
 Fixing Problems
 ---------------
 
+### General problems accessing a file
+
+Due to the nature in which FFmpegfs works, if anything goes wrong, it can only report a general error. That means, when there is a problem accessing a file, copying or opening it, you will get a "Invalid argument" or "Operation not permitted". Not really informative. There is no way to pass the original result code through the file system. 
+
+What you will have to do is refer to the syslog, system journal or to the FFmpeg log itself, optionally at a higher verbosity. If you are unable to resolve the problem yourself, feel free to create [an issue](https://github.com/nschlia/ffmpegfs/issues), stating what you have done and what has happened. Do not forget to add logs (preferably at a higher verbosity) and if possible a description how to recreate the issue. A demo file that causes the error would be helpful as well.
+
 ### Transcoding too slow
 
 See [Building FFmpeg with optimisations](INSTALL.md#building-ffmpeg-with-optimisations)