Cannot install .deb on LinuxMint 22 Wilma

Installation
1

$ sudo dpkg -i duplicati_2.0.8.1-1_all.deb
(Reading database … 575452 files and directories currently installed.)
Preparing to unpack duplicati_2.0.8.1-1_all.deb …
Unpacking duplicati (2.0.8.1-1) over (2.0.8.1-1) …
dpkg: dependency problems prevent configuration of duplicati:
duplicati depends on mono-runtime (>= 5.10.0); however:
Package mono-runtime is not installed.
duplicati depends on ca-certificates-mono; however:
Package ca-certificates-mono is not installed.
duplicati depends on libmono-2.0-1; however:
Package libmono-2.0-1 is not installed.
duplicati depends on libmono-system-core4.0-cil; however:
Package libmono-system-core4.0-cil is not installed.
duplicati depends on libmono-system-configuration4.0-cil; however:
Package libmono-system-configuration4.0-cil is not installed.
duplicati depends on libmono-system-configuration-install4.0-cil; however:
Package libmono-system-configuration-install4.0-cil is not installed.
duplicati depends on libmono-system-data4.0-cil; however:
Package libmono-system-data4.0-cil is not installed.
duplicati depends on libmono-system-drawing4.0-cil; however:
Package libmono-system-drawing4.0-cil is not installed.
duplicati depends on libmono-system-net4.0-cil; however:
Package libmono-system-net4.0-cil is not installed.
duplicati depends on libmono-system-net-http4.0-cil; however:
Package libmono-system-net-http4.0-cil is not installed.
duplicati depends on libmono-system-net-http-webrequest4.0-cil; however:
Package libmono-system-net-http-webrequest4.0-cil is not installed.
duplicati depends on libmono-system-numerics4.0-cil; however:
Package libmono-system-numerics4.0-cil is not installed.
duplicati depends on libmono-system-runtime-serialization4.0-cil; however:
Package libmono-system-runtime-serialization4.0-cil is not installed.
duplicati depends on libmono-system-servicemodel4.0a-cil; however:
Package libmono-system-servicemodel4.0a-cil is not installed.
duplicati depends on libmono-system-servicemodel-discovery4.0-cil; however:
Package libmono-system-servicemodel-discovery4.0-cil is not installed.
duplicati depends on libmono-system-serviceprocess4.0-cil; however:
Package libmono-system-serviceprocess4.0-cil is not installed.
duplicati depends on libmono-system-transactions4.0-cil; however:
Package libmono-system-transactions4.0-cil is not installed.
duplicati depends on libmono-system-web4.0-cil; however:
Package libmono-system-web4.0-cil is not installed.
duplicati depends on libmono-system-web-services4.0-cil; however:
Package libmono-system-web-services4.0-cil is not installed.
duplicati depends on libmono-system-xml4.0-cil; however:
Package libmono-system-xml4.0-cil is not installed.
duplicati depends on libmono-microsoft-csharp4.0-cil; however:
Package libmono-microsoft-csharp4.0-cil is not installed.
duplicati depends on libappindicator0.1-cil | libappindicator3-0.1-cil | libayatana-appindicator1; however:
Package libappindicator0.1-cil is not installed.
Package libappindicator3-0.1-cil is not installed.
Package libayatana-appindicator1 is not installed.
duplicati depends on gtk-sharp2; however:
Package gtk-sharp2 is not installed.

dpkg: error processing package duplicati (–install):
dependency problems - leaving unconfigured
Processing triggers for mailcap (3.70+nmu1ubuntu1) …
Processing triggers for gnome-menus (3.36.0-1.1ubuntu3) …
Processing triggers for mate-menus (1.26.1+mint1) …
Processing triggers for desktop-file-utils (0.27-2build1) …
Errors were encountered while processing:
duplicati

2

Welcome to the forum @John_Davis

Does that install dependencies? I thought that was a dpkg omission. The apt command can, however Duplicati actually recommends installing mono directly from that project per manual, however since manual stops at Ubuntu 20.04 (needs update) you can get some advice here.

It looks like your distro might have (via Ubuntu) mono 6.8.0.105 which is 2020, so a little old, although changes are few these days. Duplicati is in the process of ending its usage of mono.

An alternative to apt is probably to install from your file browser which might install by gdebi.

Duplicati 2.08.1-1 search gtk-sharp2… might be the next thing that the new LM 22 is missing, possibly due to a move to GTK 3. II don’t know if libgtk-sharp3 could easily work in its place.

Regardless, if 2.0.8.1 fails there, there are test releases such as 2.0.9.104 Canary and others