Exception while merging two subtitles

[pandrii000]

Tried to merge subtitles and got an exception.
There is a stack trace:
class java.lang.NullPointerException:null
io.github.bonigarcia.dualsub.srt.DualSrt.processDesync(DualSrt.java:254)
io.github.bonigarcia.dualsub.srt.Merger.mergeSubs(Merger.java:99)
io.github.bonigarcia.dualsub.srt.Worker.doInBackground(Worker.java:140)
io.github.bonigarcia.dualsub.srt.Worker.doInBackground(Worker.java:38)
java.desktop/javax.swing.SwingWorker$1.call(SwingWorker.java:304)
java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
java.desktop/javax.swing.SwingWorker.run(SwingWorker.java:343)
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
java.base/java.lang.Thread.run(Thread.java:834)
Star.Trek.First.Contact.1996.zip

[pandrii000]

The last archive is the subtitles that I was merging.

[pandrii000]

The issue was 3 empty lines 4518 - 4520.
I deleted 2 last lines and now it's worked.

[pandrii000]

Please, fix this bug.