Some people have the options log_mime_hdrs and log_fqdn
activated in their squid configuration.
The above options generate a log format that mysar
cannot parse.
Either learn to handle different log format, or output
a sane message when log data are not what they are
supposed to be.
I would love to help fixing a few of the PHP bugs with MySAR. I have already changed a few lines and am working on this exact problem. I know that this project has been dormant for over 9 years but I still find it very useful.
I would be happy to fork it and make my own version if you are ok with it