The indicated token appears to be the beginning of a statement that is not preceded by a separator (a comma, semicolon, or newline). Following conditional expressions inside of if, elseif, and while statements with a separator makes it clear and unambiguous where the expression ends and the next statement begins.

Sometimes, this message arises from a typographical error. For example, if you type:

when you meant to type:

then MATLAB interprets a as the conditional expression, and ~ b as a statement to execute.

If the indicated token is the beginning of the next statement, precede the statement with a comma, semicolon, or newline character. If the message is the result of a typographical error, then correct it.