[Galaxy S6 Q&A, Help & Troubleshooting] alexceltare2:
Make sure you have also selected to install "WebView" in the Gapps list. So the 'gapps-config.txt' looks something like this:

# Pico+
#CalSync # Install Google Calendar Sync (if Google Calendar is being installed)
#DialerFramework # Install Dialer Framework (Android 6.0+)
GoogleTTS # Install Google Text-to-Speech Engine (Micro+ on 5.0-, Pico+ on 6.0+)
#PackageInstallerGoogle # Install Package Installer (Android 6.0 only & Android 8.0+)

# Nano+
BatteryUsage # Install Device Health Services (Android 7.1+)
#FaceDetect # Install Face Detect Library
#FaceUnlock # Install Trusted Face
Markup # Install Markup (ARM64 + Android 9.0+)
Search # Install Google App (excluding excludes GoogleNow/PixelLauncher)
Speech # Install Offline Speech Files
Wellbeing # Install Digital Wellbeing (Android 9.0+)

# Micro+
CalendarGoogle # Install Google Calendar
ExchangeGoogle # Install Exchange Services
Gmail # Install Gmail
GoogleNow # Install Google Now Launcher (Android 4.4 only) (requires Search)
PixelIcons # Install Pixel Icons (Android 7.1 only)
PixelLauncher # Install Pixel Launcher (Android 5.0+) (requires Search and Wallpapers)
Wallpapers # Install Google Wallpapers (Android 5.0+)

# Mini+
CalculatorGoogle # Install Google Calculator (Android 5.0+)
CarrierServices # Install Carrier Services (Android 6.0+) (required for Google Messages)
ClockGoogle # Install Google Clock
Maps # Install Google Maps
Messenger # Install Google Messages (except on tablet devices) (requires Carrier Services)
Photos # Install Google Photos
TagGoogle # Install Google Tags (Android 5.0+)
YouTube # Install YouTube

# Full+
Books # Install Google Play Books
Chrome # Install Chrome
CloudPrint # Install Cloud Print
Drive # Install Google Drive
Keep # Install Keep Notes
Movies # Install Google Play Movies & TV
Music # Install Google Play Music
NewsStand # Install Google News
PlayGames # Install Google Play Games
Talkback # Install Android Accessibility Suite

# Stock+
AndroidAuto # Install Android Auto (Android 5.0+)
CameraGoogle # Install Google Camera (Android 6.0+)
ContactsGoogle # Install Google Contacts (Android 5.1+)
DialerGoogle # Install Google Phone (Android 6.0+)
Duo # Install Duo
GooglePay # Install Google Pay
KeyboardGoogle # Install Gboard
PrintServiceGoogle # Install Print Service Recommendation Service (Android 7.0+)
StorageManagerGoogle # Install Smart Storage (Android 7.0+)
Translate # Install Google Translate
VRService # Install Google VR Services (Android 7.0+)
#WebViewGoogle # Install Android System Webview (Android 5.1+) (WebViewStub is installed on Android 7.0+)
#WebViewStub # Install Android System Webview (Stub) (Android 7.0+) (See note with WebViewGoogle)

# Super+
ActionsServices # Install Actions Services (Android 9.0+)
BetterTogether # Install Better Together (Android 9.0+)
DMAgent # Install Google Apps Device Policy
Docs # Install Google Docs
Earth # Install Google Earth
Fitness # Install Google Fit
GCS # Install Google Connectivity Services (Android 5.1+) (excluding also excludes ProjectFi)
Hangouts # Install Hangouts
Indic # Install Google Indic Keyboard
Japanese # Install Google Japanese Input
Korean # Install Google Korean Input
Pinyin # Install Google Pinyin Input
ProjectFi # Install Project Fi (Android 5.1+)
Sheets # Install Google Sheets
Slides # Install Google Slides
Street # Install Google Street View
Zhuyin # Install Google Zhuyin Input