A DESCRIPTION OF THE PROBLEM :
As already mention in this Question in

StackOveflow https://stackoverflow.com/questions/49967139/java-datetimeformatter-fail-to-parse-time-string-when-seconds-and-milliseconds

This piece of code should return for this "20180301091600000" with this "yyyyMMddHHmmssSSS" patter a result : "2018-03-01T09:16:00.000" note the last part "00.000" for seconds and milliseconds.
Instead it return "2018-03-01T09:16".


REGRESSION : Last worked in version 10.0.1

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
DateTimeFormatter dtformatter = DateTimeFormatter.ofPattern("yyyyMMddHHmmssSSS");
var result = LocalDateTime.parse("20180301091600000", dtformatter);
System.out.println(result);

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
2018-03-01T09:16:00.000
ACTUAL -
2018-03-01T09:16

CUSTOMER SUBMITTED WORKAROUND :
A temporary solution is like I mentioned here https://stackoverflow.com/a/49967274/5558072

We need to parse the date with another formatter like this :

var result = LocalDateTime.parse("20180301091600001", dtformatter)
                                    .format(DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss:SSS"));

FREQUENCY : always