Unable to drag/drop widgets from designer

Qt 5.15.1 (x86_64-little_endian-lp64 shared (dynamic) release build; by Clang 10.0.0 (clang-1000.11.45.5) (Apple)) on "cocoa" 
OS: macOS 10.15 [darwin version 19.6.0]

Architecture: x86_64; features: SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 AVX AVX2

Environment:

Features: QT_NO_EXCEPTIONS QT_NO_OPENSSL

Library info:
 PrefixPath: /Users/ali/Qt/Qt Creator.app/Contents
 DocumentationPath: /Users/ali/Qt/Qt Creator.app/Contents/doc
 HeadersPath: /Users/ali/Qt/Qt Creator.app/Contents/include
 LibrariesPath: /Users/ali/Qt/Qt Creator.app/Contents/lib
 LibraryExecutablesPath: /Users/ali/Qt/Qt Creator.app/Contents/libexec
 BinariesPath: /Users/ali/Qt/Qt Creator.app/Contents/MacOS
 PluginsPath: /Users/ali/Qt/Qt Creator.app/Contents/PlugIns
 ImportsPath: /Users/ali/Qt/Qt Creator.app/Contents/Imports/qtquick1
 Qml2ImportsPath: /Users/ali/Qt/Qt Creator.app/Contents/Imports/qtquick2
 ArchDataPath: /Users/ali/Qt/Qt Creator.app/Contents
 DataPath: /Users/ali/Qt/Qt Creator.app/Contents
 TranslationsPath: /Users/ali/Qt/Qt Creator.app/Contents/translations
 ExamplesPath: /Users/ali/Qt/Qt Creator.app/Contents/examples
 TestsPath: /Users/ali/Qt/Qt Creator.app/Contents/tests
 SettingsPath: /Users/ali/Qt/Qt Creator.app/Contents

Standard paths [*...* denote writable entry]:
 DesktopLocation: "Desktop" */Users/ali/Desktop*
 DocumentsLocation: "Documents" */Users/ali/Documents*
 FontsLocation: "Fonts" */Users/ali/Library/Fonts* /Library/Fonts /System/Library/Fonts
 ApplicationsLocation: "Applications" */Users/ali/Applications* /Applications
 MusicLocation: "Music" */Users/ali/Music*
 MoviesLocation: "Movies" */Users/ali/Movies*
 PicturesLocation: "Pictures" */Users/ali/Pictures*
 TempLocation: "Temporary Items" */private/var/folders/jl/d6mjvkmj0jvf6vqtwhrq_7vm0000gn/T*
 HomeLocation: "Home" */Users/ali*
 AppLocalDataLocation: "Application Support" */Users/ali/Library/Application Support/QtProject/qtdiag* /Library/Application Support/QtProject/qtdiag /Users/ali/Qt/Qt Creator.app/Contents/Resources
 CacheLocation: "Caches" */Users/ali/Library/Caches/QtProject/qtdiag* /Library/Caches/QtProject/qtdiag
 GenericDataLocation: "Application Support" */Users/ali/Library/Application Support* /Library/Application Support
 RuntimeLocation: "Application Support" */Users/ali/Library/Application Support*
 ConfigLocation: "Preferences" */Users/ali/Library/Preferences*
 DownloadLocation: "Downloads" */Users/ali/Downloads*
 GenericCacheLocation: "Caches" */Users/ali/Library/Caches* /Library/Caches /System/Library/Caches
 GenericConfigLocation: "Preferences" */Users/ali/Library/Preferences*
 AppDataLocation: "Application Support" */Users/ali/Library/Application Support/QtProject/qtdiag* /Library/Application Support/QtProject/qtdiag /Users/ali/Qt/Qt Creator.app/Contents/Resources
 AppConfigLocation: "Preferences" */Users/ali/Library/Preferences/QtProject/qtdiag*

File selectors (increasing order of precedence):
 en_US unix darwin mac osx macos

Network:
 Using "Secure Transport, macOS 10.15", version: 0x0

Platform capabilities: ThreadedPixmaps OpenGL BufferQueueingOpenGL WindowMasks MultipleWindows ApplicationState ForeignWindows NonFullScreenWindows NativeWidgets WindowManagement RasterGLSurface ApplicationIcon

Style hints:
 mouseDoubleClickInterval: 400
 mousePressAndHoldInterval: 800
 startDragDistance: 10
 startDragTime: 500
 startDragVelocity: 0
 keyboardInputInterval: 400
 keyboardAutoRepeatRate: 30
 cursorFlashTime: 1000
 showIsFullScreen: 0
 showIsMaximized: 0
 passwordMaskDelay: 0
 passwordMaskCharacter: U+2022
 fontSmoothingGamma: 2
 useRtlExtensions: 0
 setFocusOnTouchRelease: 0
 tabFocusBehavior: Qt::TabFocusBehavior(3) 
 singleClickActivation: 0

Additional style hints (QPlatformIntegration):
 ReplayMousePressOutsidePopup: 1

Theme:
 Platforms requested : cocoa
 available : 
 Styles requested : macintosh
 available : macintosh,Windows,Fusion
 System font : ".AppleSystemUIFont" 13
 Native file dialog
 Native color dialog
 Native font dialog

Fonts:
 General font : ".AppleSystemUIFont" 13
 Fixed font : ".SF NS Mono" 10
 Title font : ".AppleSystemUIFont" 13
 Smallest font: ".AppleSystemUIFont" 9

Palette:
 QPalette::WindowText: #d8ffffff
 QPalette::Button: #ff323232
 QPalette::Light: #ff373737
 QPalette::Midlight: #ff343434
 QPalette::Dark: #ffbfbfbf
 QPalette::Mid: #ff242424
 QPalette::Text: #d8ffffff
 QPalette::BrightText: #ff373737
 QPalette::ButtonText: #ff000000
 QPalette::Base: #ff1e1e1e
 QPalette::Window: #ff323232
 QPalette::Shadow: #ff000000
 QPalette::Highlight: #ff3f638b
 QPalette::HighlightedText: #d8ffffff
 QPalette::Link: #ff419cff
 QPalette::LinkVisited: #ffff00ff
 QPalette::AlternateBase: #ff989898
 QPalette::NoRole: #ff000000
 QPalette::ToolTipBase: #3fffffff
 QPalette::ToolTipText: #ff000000
 QPalette::PlaceholderText: #80ffffff

Screens: 1, High DPI scaling: inactive
# 0 "Color LCD" Depth: 24 Primary: yes
 Manufacturer: 
 Model: 
 Serial number: 
 Geometry: 1680x1050+0+0 Available: 1680x958+0+23
 Physical size: 330.791x206.744 mm Refresh: 60 Hz Power state: 0
 Physical DPI: 129,129 Logical DPI: 72,72 Subpixel_RGB
 DevicePixelRatio: 2 Pixel density: 1
 Primary orientation: 2 Orientation: 2 Native orientation: 0 OrientationUpdateMask: 0

LibGL Vendor: Intel Inc.
Renderer: Intel(R) UHD Graphics 630
Version: 2.1 INTEL-14.7.8
Shading language: 1.20
Format: Version: 2.1 Profile: 0 Swap behavior: 2 Buffer size (RGB): 8,8,8
Profile: None (QOpenGLFunctions_-453994832_32766)

Qt Rendering Hardware Interface supported backends:
OpenGL (with default QSurfaceFormat):
 Min Texture Size: 1
 Max Texture Size: 16384
 Max Color Attachments: 8
 Frames in Flight: 1
 Uniform Buffer Alignment: 1
 Supported MSAA sample counts: 1,2,4,8,16
 Features:
 - MultisampleTexture
 v MultisampleRenderBuffer
 - DebugMarkers
 - Timestamps
 - Instancing
 - CustomInstanceStepRate
 - PrimitiveRestart
 v NonDynamicUniformBuffers
 v NonFourAlignedEffectiveIndexBufferOffset
 v NPOTTextureRepeat
 - RedOrAlpha8IsRed
 v ElementIndexUint
 - Compute
 v WideLines
 v VertexShaderPointSize
 - BaseVertex
 - BaseInstance
 v TriangleFanTopology
 v ReadBackNonUniformBuffer
 v ReadBackNonBaseMipLevel
 Texture formats: RGBA8 BGRA8 R8 R16 RED_OR_ALPHA8 BC1 BC2 BC3
Metal:
 Min Texture Size: 1
 Max Texture Size: 16384
 Max Color Attachments: 8
 Frames in Flight: 2
 Uniform Buffer Alignment: 256
 Supported MSAA sample counts: 1,2,4,8
 Features:
 v MultisampleTexture
 v MultisampleRenderBuffer
 v DebugMarkers
 - Timestamps
 v Instancing
 v CustomInstanceStepRate
 v PrimitiveRestart
 v NonDynamicUniformBuffers
 - NonFourAlignedEffectiveIndexBufferOffset
 v NPOTTextureRepeat
 v RedOrAlpha8IsRed
 v ElementIndexUint
 v Compute
 - WideLines
 v VertexShaderPointSize
 v BaseVertex
 v BaseInstance
 - TriangleFanTopology
 v ReadBackNonUniformBuffer
 v ReadBackNonBaseMipLevel
 Texture formats: RGBA8 BGRA8 R8 R16 RED_OR_ALPHA8 RGBA16F RGBA32F R16F R32F D16 D32F BC1 BC2 BC3 BC4 BC5 BC6H BC7


Plugin information:

+ Android 4.13.1
+ AutoTest 4.13.1
 AutotoolsProjectManager 4.13.1
 BareMetal 4.13.1
+ Bazaar 4.13.1
 Beautifier 4.13.1
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 Boot2Qt 4.13.1
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 ClangFormat 4.13.1
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 ClearCase 4.13.1
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 CompilationDatabaseProjectManager 4.13.1
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 Cppcheck 4.13.1
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 EmacsKeys 4.13.1
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 HelloWorld 4.13.1
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 MesonProjectManager 4.13.1
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 Nim 4.13.1
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 Perforce 4.13.1
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+ Welcome 4.13.1
 WinRt 4.13.1

Qt Creator 4.13.1
Based on Qt 5.15.1 (Clang 11.0 (Apple), 64 bit)
From revision 1da2c1f766
Built on Sep 16 2020 01:17:23