Though I've reproduced the issue, it doesn't seem to matter whether or not the text field is currently editing. Here is the full stack trace. Looks like it is just related to the animation.
java.lang.NullPointerException: Attempt to invoke virtual method 'void com.codename1.ui.Form.deregisterAnimated(com.codename1.ui.animations.Animation)' on a null object reference
12-29 10:34:46.714 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.TextField.deinitialize(TextField.java:1177)
12-29 10:34:46.714 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.Component.deinitializeImpl(Component.java:4233)
12-29 10:34:46.714 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.TextArea.deinitializeImpl(TextArea.java:565)
12-29 10:34:46.714 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.Container.removeComponentImplNoAnimationSafety(Container.java:907)
12-29 10:34:46.714 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.Container$3.updateState(Container.java:890)
12-29 10:34:46.714 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.animations.ComponentAnimation.updateAnimationState(ComponentAnimation.java:80)
12-29 10:34:46.714 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.AnimationManager.updateAnimations(AnimationManager.java:61)
12-29 10:34:46.715 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.Form.repaintAnimations(Form.java:1301)
12-29 10:34:46.715 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.Display.edtLoopImpl(Display.java:1077)
12-29 10:34:46.715 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.Display.mainEDTLoop(Display.java:994)
12-29 10:34:46.715 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.ui.RunnableWrapper.run(RunnableWrapper.java:120)
12-29 10:34:46.715 32368-32392/com.codename1.tests.textediting W/System.err: at com.codename1.impl.CodenameOneThread$1.run(CodenameOneThread.java:60)
12-29 10:34:46.715 32368-32392/com.codename1.tests.textediting W/System.err: at java.lang.Thread.run(Thread.java:818)
In any case. I'm looking into this now and should have a fix soon.
Steve