Hi salvadorsosa,
Thanks for getting in touch. Sorry to hear that!

I've added this to our list to investigate, and we'll let you know when we have an update!

Hi salvadorsosa,
We are tracking this in an upstream issue and hope to have a change released soon.

If you're able to manage this manually in the meantime, that may work, or it may only be possible to use the web app until this is changed.

Let us know if we can help with anything else!

Hi Andrewski. Reading the issue, looks like a lot of people fixed it just making that library optional and rebuilding the .deb package. This will not allow to have the icon on the tray but will allow to install and use the application.

In case the someone needs to install RTM in Debian 11 (Bullseye), you can download the .deb file manually and installed using the following command:

$ sudo dpkg --ignore-depends=libappindicator3-1 -i rememberthemilk_1.3.11_amd64.deb

That will not provide the notifications, but will let you use the other application features.

Forget the previous suggestion as can break the package system. A better option is install the libraries from buster.

$ wget http://ftp.us.debian.org/debian/pool/main/libi/libindicator/libindicator3-7_0.5.0-4_amd64.deb

$ wget http://ftp.us.debian.org/debian/pool/main/liba/libappindicator/libappindicator3-1_0.4.92-7_amd64.deb

$ sudo dpkg -i libindicator3-7_0.5.0-4_amd64.deb

$ sudo dpkg -i libappindicator3-1_0.4.92-7_amd64.deb

and finally

$ sudo dpkg -i rememberthemilk_1.3.11_amd64.deb

if something is missing to install:

$ sudo apt -f install

Now everything is working. Case closed. Dec 2021.