NPE while trying to send MCM to external account

[Azazorro]

Running mojo-2.4-0-20200115.jar on Ubuntu 20.04, java -version: openjdk version "11.0.11" 2021-04-20

When I try to add external address I want to send MCM too using Import -> (inserting tag) -> Add to wallet, I get a pop up window with the following text:

<!> Error
null

java.lang.NullPointerException
org.mochimo.mojo.gui.swing.Settings.getMillisecAsDuration(Settings.java:468)
org.mochimo.mojo.gui.swing.GUI.getArchivables(GUI.java:120)
org.mochimo.mojo.gui.swing.tasks.ImportAccountTask.task(ImportAccountTask.java:123)
org.mochimo.mojo.gui.swing.tasks.AbstractGUITask.run(AbstractGUITask.java:52)
java.base/java.lang.Thread.run(Thread.java:829)

-----------------------------------------------------

When I try to use Send button entering tag as destination address I get the following (slightly different) pop-up window:

<!> Error
null

java.lang.NullPointerException
org.mochimo.mojo.gui.swing.Settings.getMillisecAsDuration(Settings.java:468)
org.mochimo.mojo.gui.swing.GUI.getArchivables(GUI.java:120)
org.mochimo.mojo.gui.swing.tasks.AddAccountTask.task(AddAccountTask.java:108)
org.mochimo.mojo.gui.swing.tasks.SpendTask.task(SpendTask.java:158)
org.mochimo.mojo.gui.swing.tasks.AbstractGUITask.run(AbstractGUITask.java:52)
java.base/java.lang.Thread.run(Thread.java:829)

-----------------------------------------------------

Parsing payment amount
Activating new change address

Am I doing something wrong? Why can getMillisecAsDuration fail on my system?
Thanks in advance!

[Azazorro]

Looks like I've found a workaround, everything works after I've removed mojo.gui.settings.properties file and started mojo once again. Newly generated file contains wallet.archive.delay=17280000 line and the old one doesn't have any wallet.archive.delay value. This could be probably fixed by adding wallet.archive.delay to properties file instead of NPE exceptions if there is no wallet.archive.delay, exceptions look really scary.