Sometimes i am getting Argument Error while scrolling. This is very random.

[varunn12]

Launching lib\main.dart on LG H870DS in debug mode...
Built build\app\outputs\apk\debug\app-debug.apk.
I/FlutterActivityDelegate(11768): onResume setting current activity to this
I/ViewRootImpl(11768): ViewRoot's Touch Event : ACTION_DOWN
D/BezellessGripSuppressionFilter(11768): Filter[0] Ignore
D/BezellessGripSuppressionFilter(11768): mMiddleGripMask[0]
I/ViewRootImpl(11768): ViewRoot's Touch Event : ACTION_UP
I/ViewRootImpl(11768): ViewRoot's Touch Event : ACTION_DOWN
D/BezellessGripSuppressionFilter(11768): Filter[1] Ignore
D/BezellessGripSuppressionFilter(11768): mMiddleGripMask[1]
I/ViewRootImpl(11768): ViewRoot's Touch Event : ACTION_UP
I/ViewRootImpl(11768): ViewRoot's Touch Event : ACTION_DOWN
I/ViewRootImpl(11768): ViewRoot's Touch Event : ACTION_UP
I/ViewRootImpl(11768): ViewRoot's KeyEvent { action=ACTION_DOWN, keyCode=KEYCODE_BACK, scanCode=0, metaState=0, flags=0x48, repeatCount=0, eventTime=112724507, downTime=112724507, deviceId=-1, source=0x101 } to DecorView@2e485f1[MainActivity]
I/ViewRootImpl(11768): ViewRoot's KeyEvent { action=ACTION_UP, keyCode=KEYCODE_BACK, scanCode=0, metaState=0, flags=0x48, repeatCount=0, eventTime=112724581, downTime=112724507, deviceId=-1, source=0x101 } to DecorView@2e485f1[MainActivity]
I/ViewRootImpl(11768): ViewRoot's Touch Event : ACTION_DOWN
I/ViewRootImpl(11768): ViewRoot's Touch Event : ACTION_UP
I/flutter (11768): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (11768): The following ArgumentError was thrown during performLayout():
I/flutter (11768): Invalid argument(s)
I/flutter (11768):
I/flutter (11768): When the exception was thrown, this was the stack:
I/flutter (11768): #0 _StringBase.+ (dart:core/runtime/libstring_patch.dart:245:57)
I/flutter (11768): #1 MyHomePage.build.. (file:///G:/FlutterProjects/bloc_project/lib/main.dart:72:77)
I/flutter (11768): #2 SliverChildBuilderDelegate.build (package:flutter/src/widgets/sliver.dart:197:20)
I/flutter (11768): #3 SliverMultiBoxAdaptorElement._build. (package:flutter/src/widgets/sliver.dart:716:67)
I/flutter (11768): #4 _HashMap.putIfAbsent (dart:collection/runtime/libcollection_patch.dart:143:29)
I/flutter (11768): #5 SliverMultiBoxAdaptorElement._build (package:flutter/src/widgets/sliver.dart:716:26)
I/flutter (11768): #6 SliverMultiBoxAdaptorElement.createChild. (package:flutter/src/widgets/sliver.dart:729:55)
I/flutter (11768): #7 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2222:19)
I/flutter (11768): #8 SliverMultiBoxAdaptorElement.createChild (package:flutter/src/widgets/sliver.dart:722:11)
I/flutter (11768): #9 RenderSliverMultiBoxAdaptor._createOrObtainChild. (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:254:23)
I/flutter (11768): #10 RenderObject.invokeLayoutCallback. (package:flutter/src/rendering/object.dart:1666:58)
I/flutter (11768): #11 PipelineOwner._enableMutationsToDirtySubtrees (package:flutter/src/rendering/object.dart:740:15)
I/flutter (11768): #12 RenderObject.invokeLayoutCallback (package:flutter/src/rendering/object.dart:1666:13)
I/flutter (11768): #13 RenderSliverMultiBoxAdaptor._createOrObtainChild (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:243:5)
I/flutter (11768): #14 RenderSliverMultiBoxAdaptor.insertAndLayoutChild (package:flutter/src/rendering/sliver_multi_box_adaptor.dart:381:5)
I/flutter (11768): #15 RenderSliverList.performLayout.advance (package:flutter/src/rendering/sliver_list.dart:190:19)
I/flutter (11768): #16 RenderSliverList.performLayout (package:flutter/src/rendering/sliver_list.dart:233:19)
I/flutter (11768): #17 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (11768): #18 RenderSliverPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:182:11)
I/flutter (11768): #19 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (11768): #20 RenderViewportBase.layoutChildSequence (package:flutter/src/rendering/viewport.dart:336:13)
I/flutter (11768): #21 RenderViewport._attemptLayout (package:flutter/src/rendering/viewport.dart:1172:12)
I/flutter (11768): #22 RenderViewport.performLayout (package:flutter/src/rendering/viewport.dart:1090:20)
I/flutter (11768): #23 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1445:7)
I/flutter (11768): #24 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:709:18)
I/flutter (11768): #25 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:270:19)
I/flutter (11768): #26 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:627:13)
I/flutter (11768): #27 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:208:5)
I/flutter (11768): #28 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
I/flutter (11768): #29 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
I/flutter (11768): #30 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:842:5)
I/flutter (11768): #31 _invoke (dart:ui/hooks.dart:120:13)
I/flutter (11768): #32 _drawFrame (dart:ui/hooks.dart:109:3)
I/flutter (11768):
I/flutter (11768): The following RenderObject was being processed when the exception was fired:
I/flutter (11768): RenderSliverList#08ab6 relayoutBoundary=up2
I/flutter (11768): creator: SliverList ← MediaQuery ← SliverPadding ← Viewport ← _ScrollableScope ←
I/flutter (11768): IgnorePointer-[GlobalKey#85f7b] ← Semantics ← Listener ← _GestureSemantics ←
I/flutter (11768): RawGestureDetector-[LabeledGlobalKey#92e9f] ←
I/flutter (11768): _ExcludableScrollSemantics-[GlobalKey#6b5a8] ← RepaintBoundary ← ⋯
I/flutter (11768): parentData: paintOffset=Offset(0.0, 0.0) (can use size)
I/flutter (11768): constraints: SliverConstraints(AxisDirection.down, GrowthDirection.forward,
I/flutter (11768): ScrollDirection.reverse, scrollOffset: 574.0, remainingPaintExtent: 619.9, crossAxisExtent: 423.5,
I/flutter (11768): crossAxisDirection: AxisDirection.right, viewportMainAxisExtent: 619.9, remainingCacheExtent:
I/flutter (11768): 1119.9 cacheOrigin: -250.0 )
I/flutter (11768): geometry: SliverGeometry(scrollExtent: 2608.0, paintExtent: 619.9, maxPaintExtent: 2608.0,
I/flutter (11768): hasVisualOverflow: true, cacheExtent: 1119.9)
I/flutter (11768): currently live children: 2 to 10
I/flutter (11768): This RenderObject had the following descendants (showing up to depth 5):
I/flutter (11768): RenderRepaintBoundary#18ff3 relayoutBoundary=up3
I/flutter (11768): RenderSemanticsGestureHandler#015a3 relayoutBoundary=up4
I/flutter (11768): RenderPointerListener#c3a82 relayoutBoundary=up5
I/flutter (11768): RenderSemanticsAnnotations#918d3 relayoutBoundary=up6
I/flutter (11768): RenderPadding#4edc5 relayoutBoundary=up7
I/flutter (11768): RenderRepaintBoundary#376be relayoutBoundary=up3
I/flutter (11768): RenderSemanticsGestureHandler#e66b4 relayoutBoundary=up4
I/flutter (11768): RenderPointerListener#a2e47 relayoutBoundary=up5
I/flutter (11768): RenderSemanticsAnnotations#cc5c2 relayoutBoundary=up6
I/flutter (11768): RenderPadding#4150a relayoutBoundary=up7
I/flutter (11768): RenderRepaintBoundary#8ab07 relayoutBoundary=up3
I/flutter (11768): RenderSemanticsGestureHandler#f969e relayoutBoundary=up4
I/flutter (11768): RenderPointerListener#303a9 relayoutBoundary=up5
I/flutter (11768): RenderSemanticsAnnotations#50415 relayoutBoundary=up6
I/flutter (11768): RenderPadding#ae58d relayoutBoundary=up7
I/flutter (11768): RenderRepaintBoundary#867d2 relayoutBoundary=up3
I/flutter (11768): RenderSemanticsGestureHandler#e4adc relayoutBoundary=up4
I/flutter (11768): RenderPointerListener#4de00 relayoutBoundary=up5
I/flutter (11768): RenderSemanticsAnnotations#057d5 relayoutBoundary=up6
I/flutter (11768): RenderPadding#c9e9c relayoutBoundary=up7
I/flutter (11768): RenderRepaintBoundary#74bb2 relayoutBoundary=up3
I/flutter (11768): RenderSemanticsGestureHandler#80263 relayoutBoundary=up4
I/flutter (11768): RenderPointerListener#2d321 relayoutBoundary=up5
I/flutter (11768): RenderSemanticsAnnotations#3d7cd relayoutBoundary=up6
I/flutter (11768): RenderPadding#ff3a8 relayoutBoundary=up7
I/flutter (11768): ...(descendants list truncated after 25 lines)
I/flutter (11768):

[figengungor]

Hi! It's related to string concatenation with + operator when posterPath is null. So you can either
use String interpolation like that:

String imageUrl = "https://image.tmdb.org/t/p/w92${snapshot.data[index].posterPath}"

or check if posterPath is null like that:

  String imageUrl = "https://image.tmdb.org/t/p/w92"
                          + (snapshot.data[index].posterPath ?? "");