I created a file with the contents mentioned in comment #23, but this hasn't solved it. Instead I get the following error message now when I install or remove any package:
Entfernen von libavahi-ui-gtk3-0:amd64 ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libgvc5 ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libgraph4 ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libcdt4 ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libchamplain-gtk-0.12-0:amd64 ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libchamplain-0.12-0:amd64 ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libstreamanalyzer0 ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libsoprano4 ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libclucene0ldbl ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libdlrestrictions1 ...
Unknown configuration key `foreign-architecture' found in your `dpkg'
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
I created a file with the contents mentioned in comment #23, but this hasn't solved it. Instead I get the following error message now when I install or remove any package:
Entfernen von libavahi- ui-gtk3- 0:amd64 ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libgvc5 ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libgraph4 ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libcdt4 ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libchamplain- gtk-0.12- 0:amd64 ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libchamplain- 0.12-0: amd64 ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libstreamanalyzer0 ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libsoprano4 ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libclucene0ldbl ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.
Entfernen von libdlrestrictions1 ... architecture' found in your `dpkg'
Unknown configuration key `foreign-
configuration files. This warning will become a hard error at a later
date, so please remove the offending configuration options and replace
them with `dpkg --add-architecture' invocations at the command line.