Unity Tweak tool fails to start with the error "com.canonical.unity.webapps schema is missing"

Question

com.canonical.unity.webapps
In order to work properly, Unity Tweak Tool recommends you install the necessary packages

Answer 1

Install the package unity-webapps-service

Answer 2

Just a command line way to do jackyzy823's answer:

mkdir tweak;cd tweak
sudo apt-get download unity-webapps-service
ar xvf *
tar xvf data*
sudo mv usr/share/glib-2.0/schemas/com.canonical.unity.webapps.gschema.xml /usr/share/glib-2.0/schemas/
sudo glib-compile-schemas /usr/share/glib-2.0/schemas/
cd ..; sudo rm -Rf tweak

Answer 3

A tricky way for this,because i do not want to download so many dependencies for unity-webapps-service.

extract the file com.canonical.unity.webapps.gschema.xml (you can see it in http://packages.ubuntu.com/trusty/amd64/unity-webapps-service/filelist) in package unity-webapps-service,put this file to /usr/share/glib-2.0/schemas/ and finally sudo glib-compile-schemas /usr/share/glib-2.0/schemas/ and it works.

Answer 4

Simple solution.

Just Install necessary packages.

sudo apt-get install unity-webapps-common

Answer 5

I had no problem installing webapps service and webapps common. My exact problem was the package

 com.canonical.unity.FileLens

was missing. I misread the screenshot in this question, and spent more than half an hour trying to figure out why even though unity webapps service and webapps common are installed unity tweak tool is not working. Finally I found out the above package was missing instead of the one mentioned in the screenshot.

To solve this error, install the unity-lens-files package

sudo apt-get install unity-lens-files

That's it. Unity Tweak Tool is now working! (finally!)

Answer 6

In case of Ubuntu 19 or later, install the unity-lens-applications package by running:

sudo apt install unity-lens-applications

Answer 7

For those who still need a solution: the problem occurs if one uninstalls the overlay scrollbars. To solve the problem, install the overlay scroll bars again (sudo apt-get install overlay-scrollbar) and disable them via the Unity Tweak Tool itself. (System > Scrolling)

Answer 8

Simple, and effective type

sudo apt-get install unity-webapps-common unity-webapps-service

into the terminal

Answer 9

Go to the terminal and run the following commands. This works for me. Hope it works for you.

sudo apt-get install --reinstall notify-osd
sudo apt-get install --reinstall overlay-scrollbar

Answer 10

You need is to use synaptic. Try these:

1. Install synaptic: "sudo apt-get install synaptic" in the terminal.
2. Open Synaptic from the dash or from terminal sudo synaptic.
3. Click on Custom Filters then Missing Recommended Packages.
4. Highlight all and right click mark for installation
5. Click apply on the toolbar.