In jEdit 4.1, the mode file grammar has been cleaned up somewhat. As a result, some edit modes written for jEdit 4.0 and earlier need to be updated:
Defining <WHITESPACE> rules is no longer necessary and doing so will print warnings to the activity logs.
The <KEYWORDS> tag no longer accepts an IGNORE_CASE attribute. Set the IGNORE_CASE attribute of the <RULES> tag instead.
The <END> tag of the <SPAN> rule used to be optional, in which case any occurrence of the start string would cause the remainder of the buffer to be highlighted with the span. In jEdit 4.1, the <END> tag can no longer be omitted, however a <SEQ> tag with a DELEGATE attribute can be used to achieve the same effect as endless span.
Defining <SEQ TYPE="NULL"> rules for word separators is no longer necessary. Now, any non-alphanumeric character not appearing in a keyword definition or the ruleset's NO_WORD_SEP attribute is considered a word separator.