title: Failed assertion: 'owner!._debugCurrentBuildTarget == this': is not true
body: <p>So i am building an to do list app using slidable as Task-Element. However If i want to add a nth task to my database (Sqflite) this error shows up, :</p>
  <pre><code>
  The relevant error-causing widget was: 
    MaterialApp MaterialApp:file:///C:/Users/Thana/StudioProjects/taskStack/lib/main.dart:15:12
  When the exception was thrown, this was the stack: 
  #2      Element.rebuild.&lt;anonymous closure&gt; (package:flutter/src/widgets/framework.dart:4479:14)
  #3      Element.rebuild (package:flutter/src/widgets/framework.dart:4482:6)
  #4      ProxyElement.update (package:flutter/src/widgets/framework.dart:5108:5)
  #5      Element.updateChild (package:flutter/src/widgets/framework.dart:3501:15)
  #6      ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4780:16)
  #7      Element.rebuild (package:flutter/src/widgets/framework.dart:4477:5)
  #8      ProxyElement.update (package:flutter/src/widgets/framework.dart:5108:5)
  #9      Element.updateChild (package:flutter/src/widgets/framework.dart:3501:15)
  #10     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4780:16)
  #11     StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4928:11)
  #12     Element.rebuild (package:flutter/src/widgets/framework.dart:4477:5)
  #13     StatefulElement.update (package:flutter/src/widgets/framework.dart:4960:5)
  #14     Element.updateChild (package:flutter/src/widgets/framework.dart:3501:15)
  #15     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4780:16)
  #16     StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4928:11)
  #17     Element.rebuild (package:flutter/src/widgets/framework.dart:4477:5)
  #18     StatefulElement.update (package:flutter/src/widgets/framework.dart:4960:5)
  #19     Element.updateChild (package:flutter/src/widgets/framework.dart:3501:15)
  #20     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4780:16)
  #21     StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4928:11)
  #22     Element.rebuild (package:flutter/src/widgets/framework.dart:4477:5)
  #23     BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2659:19)
  #24     WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:882:21)
  #25     RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:363:5)
  #26     SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1144:15)
  #27     SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1081:9)
  #28     SchedulerBinding.scheduleWarmUpFrame.&lt;anonymous closure&gt; (package:flutter/src/scheduler/binding.dart:862:7)
  (elided 6 frames from class _AssertionError, class _RawReceivePortImpl, class _Timer, and dart:async-patch)
  
  </code></pre>