Thank you for your report. The message is generated as MLA is loading a file with MIME type definitions, and it indicates some kind of damage in the file. This happened to one other MLA user over a year ago but I was never able to identify the specific cause of the problem.
I have uploaded a new MLA Development Version with some code that writes an entry to the error log and ignores the damaged line(s). The error log entry will indicate what the damaged line contains.
If you install the Development Version (or re-install the current official version) you will get a fresh copy of the file and the problem may just go away. If not, the error log will help me identify the problem. To get the Development Version, follow the instructions in this earlier topic:
Shortcode not working in (special) widget
If you still have trouble after updating to the Development Version, let me know what message(s) are written to the error log. You can get easy access to the error log by following the debug instructions in this earlier topic:
plugin setting page is blank with WP 4.4
It would be great if you can try the Development Version and let me know if the fix works for you. Thanks for your help and your patience.
Thank you for the quick answer. With the development version the problem seems to be fixed. I will check if everything works as expected.
I have released MLA version 2.22, which contains the fix for this issue. I am marking the topic resolved, but please update it if you have any other problems with the MIME type support. Thanks again for alerting me to the problem and for your interest in the plugin.
