Nextcloud client install RHEL7.9

🚧 Installation
1

Attempting to install Nextcloud-3.2.1-x86_64.AppImage (or Nextcloud-2.6.5-x86_64.AppImage) on RHEL7.9. When running the .AppImage, it whines:

[so-and-so@somewhere Downloads]$ ./Nextcloud-3.2.1-x86_64.AppImage
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by ./Nextcloud-3.2.1-x86_64.AppImage) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version GLIBCXX_3.4.21’ not found (required by ./Nextcloud-3.2.1-x86_64.AppImage)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5QuickControls2.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5WebEngineWidgets.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5WebEngineCore.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version GLIBCXX_3.4.21’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5WebEngineCore.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version GLIBCXX_3.4.20' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5WebEngineCore.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5Quick.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5Qml.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version GLIBCXX_3.4.20’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5Qml.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5Svg.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5Xml.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version GLIBCXX_3.4.21' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libnextcloudsync.so.0) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libnextcloudsync.so.0)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libnextcloud_csync.so.0) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5Network.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5Widgets.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5Gui.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5DBus.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5Core.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.8' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5Core.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version GLIBCXX_3.4.21’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5Core.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5QuickTemplates2.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5PrintSupport.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5QuickWidgets.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5WebChannel.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.8' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5Positioning.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5Positioning.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version GLIBCXX_3.4.21' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libQt5Positioning.so.5) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.9’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libQt5WebSockets.so.5)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.8' not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/../lib/libicui18n.so.55) ./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libstdc++.so.6: version CXXABI_1.3.8’ not found (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libicuuc.so.55)
./Nextcloud-3.2.1-x86_64.AppImage: /lib64/libgpg-error.so.0: no version information available (required by /tmp/.mount_Nextclvj5EbW/usr/bin/…/lib/libgcrypt.so.20)