Android Messaging SDK: NullPointerException when trying to open attachment

In our Android project we use Zendesk Messaging SDK. If there is a file in .mp4 format attached to a message in the chat, when user taps on this attachment the application crashes with NullPointerException. With other types of files it seems work correctly.

Versions of SDK libraries as follows:

zendesk_chat = "3.3.6"
zendesk_messaging = "5.2.5"

java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.startsWith(java.lang.String)' on a null object reference
                                            at zendesk.messaging.ui.UtilsAttachment.openAttachment(UtilsAttachment.java:56)
                                            at zendesk.messaging.ui.UtilsEndUserCellView$3.onClick(UtilsEndUserCellView.java:258)
                                            at android.view.View.performClick(View.java:7441)
                                            at android.view.View.performClickInternal(View.java:7418)
                                            at android.view.View.access$3700(View.java:835)
                                            at android.view.View$PerformClick.run(View.java:28676)
                                            at android.os.Handler.handleCallback(Handler.java:938)
                                            at android.os.Handler.dispatchMessage(Handler.java:99)
                                            at android.os.Looper.loopOnce(Looper.java:201)
                                            at android.os.Looper.loop(Looper.java:288)
                                            at android.app.ActivityThread.main(ActivityThread.java:7839)
                                            at java.lang.reflect.Method.invoke(Native Method)
                                            at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
                                            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)