Why does MATLAB crash when editing a script?

When editing a script or a live script MATLAB crashes.

Error is thrown in the Command Window:

Exception in thread "AWT-EventQueue-0": java.lang.NullPointerException
 at java.util.WeakHashMap.hash(WeakHashMap.java:298)
 at java.util.WeakHashMap.get(WeakHashMap.java:396)
 at java.util.Collections$SynchronizedMap.get(Collections.java:2584)
 at sun.awt.SunToolkit.targetToAppContext(SunToolkit.java:399)
 at java.awt.event.FocusEvent.getOppositeComponent(FocusEvent.java:221)
...
 at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
 at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
 at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

Stack trace is:

[  0] 0x0000000010b5b603 C:\Program Files\MATLAB\R2019b\bin\win64\libmwfl.dll+00046595
[  1] 0x0000000010b595d8 C:\Program Files\MATLAB\R2019b\bin\win64\libmwfl.dll+00038360
[  2] 0x0000000010b5f58a C:\Program Files\MATLAB\R2019b\bin\win64\libmwfl.dll+00062858
[  3] 0x0000000010b5e1a8 C:\Program Files\MATLAB\R2019b\bin\win64\libmwfl.dll+00057768
[  4] 0x0000000010b63aab C:\Program Files\MATLAB\R2019b\bin\win64\libmwfl.dll+00080555
[  5] 0x00000000452e7f31   C:\Program Files\MATLAB\R2019b\bin\win64\jmi.dll+00818993
[  6] 0x0000000057909ead C:\Program Files\MATLAB\R2019b\sys\java\jre\win64\jre\bin\server\jvm.dll+02727597
[  7] 0x00000000578f208b C:\Program Files\MATLAB\R2019b\sys\java\jre\win64\jre\bin\server\jvm.dll+02629771
[  8] 0x000000005790ac26 C:\Program Files\MATLAB\R2019b\sys\java\jre\win64\jre\bin\server\jvm.dll+02731046
[  9] 0x000000005790f52d C:\Program Files\MATLAB\R2019b\sys\java\jre\win64\jre\bin\server\jvm.dll+02749741
[ 10] 0x00000000579a5d98 C:\Program Files\MATLAB\R2019b\sys\java\jre\win64\jre\bin\server\jvm.dll+03366296
[ 11] 0x00007ff9e8ec121f                      C:\WINDOWS\SYSTEM32\ntdll.dll+00659999
[ 12] 0x00007ff9e8e8a289                      C:\WINDOWS\SYSTEM32\ntdll.dll+00434825
[ 13] 0x00007ff9e8ebfe8e                      C:\WINDOWS\SYSTEM32\ntdll.dll+00654990
[ 14] 0x000000008b5c1df4                                   <unknown-module>+00000000

Answer 1

[MathWorks Support Team]

The crash might occur if you have Open JDK installed instead of the standard JDK. You can uninstall Open JDK and install standard JDK to fix the crash.