(Ubuntu 18.04 LTS) Could not load file or assembly 'netstandard, Version=2.0.0.0

1

I’m encountering the following errors when attempting to run a backup job under Ubuntu 18.04 LTS. Mono version is 6.12.0.200. Duplicati - 2.0.7.1_beta_2023-05-25

(in Web interface)
Could not load file or assembly ‘netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51’ or one of its dependencies.

(at Ubuntu command line)
Failed to load module “canberra-gtk-module”
Failed to send notification: System.IO.FileNotFoundException: Could not load file or assembly ‘notify-sharp, Version=0.4.0.0, Culture=neutral, PublicKeyToken=2df29c54e245917a’ or one of its dependencies.
File name: ‘notify-sharp, Version=0.4.0.0, Culture=neutral, PublicKeyToken=2df29c54e245917a’
at Duplicati.GUI.TrayIcon.GtkRunner.NotifyUser (System.String title, System.String message, Duplicati.GUI.TrayIcon.NotificationType type) [0x00002] in <9128bf13baf6406fa6155e78725fe6c0>:0

I am trying to backup to Backblaze B2.

Thanks for your help!

2

Was it ever working?

Have you installed these packages from the Install guide:

sudo apt install mono-devel gtk-sharp2

At least the GTK seems to be part of the problem, and I think the default mono package doesn’t have all the libraries.

3

netstandard is part of Mono. Mono itself is loaded in Ubuntu using a PPA, that is, it’s basically not supported in any way by Ubuntu. This means that to get support, you have to rely on Mono and exclusively on Mono. And it’s not realist to expect Mono to support an obsolete operating system.
In other words, sorry, but it will most probably not work.

4

Welcome to the forum @geee1w

Supported by this forum post and a 2013 decision from the mono devs, still with an open issue on

Please see if following the installation directions provides you with assemblies reported as missing.
Attempting to trace with dpkg and apt series of tools gave a clearer answer for mono than graphics.

5

No its a new install. I encounter these errors when trying to install those packages:

The following packages have unmet dependencies:
gtk-sharp2-gapi : Depends: libc6 (>= 2.31) but 2.27-3ubuntu1.6 is to be installed or
libc6.1 (>= 2.31) but it is not installable or
libc0.1 (>= 2.31) but it is not installable
libgdiplus : Depends: libc6 (>= 2.29) but 2.27-3ubuntu1.6 is to be installed
libglib2.0-cil : Depends: libglib2.0-0 (>= 2.64.1) but 2.56.4-0ubuntu0.18.04.9 is to be installed
libgtk2.0-cil : Depends: libatk1.0-0 (>= 2.35.1) but 2.28.1-1 is to be installed
Depends: libgdk-pixbuf2.0-0 (>= 2.40.0+dfsg) but 2.36.11-2 is to be installed
Depends: libglib2.0-0 (>= 2.64.1) but 2.56.4-0ubuntu0.18.04.9 is to be installed
Depends: libpango-1.0-0 (>= 1.44.7) but 1.40.14-1ubuntu0.1 is to be installed
Depends: libpangocairo-1.0-0 (>= 1.44.7) but 1.40.14-1ubuntu0.1 is to be installed

I think this means I need to update to ubuntu 22 but I’m not sure. Instructions on the duplicati site don’t mention the minimum OS version.

6

Did you make this file, per the directions?

$ cat /etc/apt/sources.list.d/mono-official-stable.list
deb https://download.mono-project.com/repo/ubuntu stable-bionic main
$

I’m not sure where your gtk-sharp2-gapi is coming from. You could try a command like:

$ apt show --all-versions gtk-sharp2
Package: gtk-sharp2
Version: 2.12.45-0xamarin19+ubuntu1804b1
Priority: optional
Section: libs
Maintainer: Debian CLI Libraries Team <pkg-cli-libs-team@lists.alioth.debian.org>
Installed-Size: 147 kB
Depends: gtk-sharp2-examples (= 2.12.45-0xamarin19+ubuntu1804b1), gtk-sharp2-gapi (= 2.12.45-0xamarin19+ubuntu1804b1), libglade2.0-cil-dev (= 2.12.45-0xamarin19+ubuntu1804b1), libglib2.0-cil-dev (= 2.12.45-0xamarin19+ubuntu1804b1), libgtk2.0-cil-dev (= 2.12.45-0xamarin19+ubuntu1804b1), monodoc-gtk2.0-manual (= 2.12.45-0xamarin19+ubuntu1804b1)
Homepage: http://www.mono-project.com/GtkSharp
Download-Size: 142 kB
APT-Manual-Installed: yes
APT-Sources: https://download.mono-project.com/repo/ubuntu stable-bionic/main amd64 Packages
Description: GTK# 2.12 suite, CLI bindings for GTK+
 GTK# 2.12 is a CLI (.NET) language binding for the GTK+ 2.12 toolkit
 .
 gtk-sharp2 is a metapackage containing dependencies for the GTK# 2.12 suite.

Package: gtk-sharp2
Version: 2.12.40-2
Priority: optional
Section: universe/libs
Origin: Ubuntu
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Debian CLI Libraries Team <pkg-cli-libs-team@lists.alioth.debian.org>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 148 kB
Depends: gtk-sharp2-examples (= 2.12.40-2), gtk-sharp2-gapi (>= 2.12.40-2), gtk-sharp2-gapi (<< 2.12.40-2.~), libglade2.0-cil-dev (>= 2.12.40-2), libglade2.0-cil-dev (<< 2.12.40-2.~), libglib2.0-cil-dev (>= 2.12.40-2), libglib2.0-cil-dev (<< 2.12.40-2.~), libgtk2.0-cil-dev (>= 2.12.40-2), libgtk2.0-cil-dev (<< 2.12.40-2.~), monodoc-gtk2.0-manual (= 2.12.40-2)
Homepage: http://www.mono-project.com/GtkSharp
Download-Size: 1,844 B
APT-Sources: http://archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
Description: GTK# 2.10 suite, CLI bindings for GTK+
 GTK# 2.10 is a CLI (.NET) language binding for the GTK+ 2.10 toolkit
 .
 gtk-sharp2 is a metapackage containing dependencies for the GTK# 2.10 suite.

$

This is Linux Mint 19.3, based on Ubuntu 18.04, and you can see I got the mono-project.com lib.