Android app stays invisible (Error "Failed to find top fullscreen for task")

REPRODUCIBILITY (% or how often): 100%
BUILD ID = OS VERSION (Settings > About product): 4.3.0.12
HARDWARE (XA2, X10, X10 II, …): XA2
REGRESSION: (compared to previous public release: Yes, No, ?): Yes

DESCRIPTION:

App that is intended to show above another Android app (even if that app was Home) stays invisible. Related log line:
W WindowManager: TaskSnapshotSurface.create: Failed to find top fullscreen for task={taskId=197 appTokens=[AppWindowToken{4183277 token=Token{a55cc76 ActivityRecord{847a311 u0 de.grobox.blitzmail/.NoteActivity t197}}}] mdr=false}

Full log: Launching BlitzNote (BlitzMail) fails - #2 by hhead

STEPS TO REPRODUCE:

  1. Touch BlitzNote app icon
  2. Note that app doesn’t come up

EXPECTED RESULT:

App should show. On Xperia X it used to show simply with a black background.

ACTUAL RESULT:

App not shown

ADDITIONAL INFORMATION:

When making sure that there’s an Android app currently occupying the screen, the app does show. For example, this works:

apkd-launcher de.grobox.blitzmail.apk de.grobox.blitzmail/de.grobox.blitzmail.MainActivity &
sleep 1 &&
apkd-launcher de.grobox.blitzmail.apk de.grobox.blitzmail/de.grobox.blitzmail.NoteActivity