MultiMarkdown mode not recognizing 'format: complete' on first line (should be case insensitive for keys)
Metadata keys are case insensitive and stripped of all spaces during processing. This means that Base Header Level, base headerlevel, and baseheaderlevel are all the same.
However, in MultiMarkdown.tmLanguage, the check for "Format: complete" on the first line is case sensitive:
Changing it to the following fixes the problem:
Customer support service by UserEcho