Ubuntu Software Center - Error - "cannot perform the following tasks"

Question

From Ubuntu Software Center, I tried to install "GTK Common Themes". During the installation halfway through the process I get the following error message:

Unable to install "GTK Common Themes"; cannot perform the following tasks:

Solution

Make sure that the list of available software is up-to-date before trying to install GTK Common Themes. In all currently supported versions of Ubuntu, open the terminal and type:

sudo apt update   
sudo snap install gtk-common-themes 

Comments

[Mark Kirby]

Please provide the error in full, you left out the most important bit.

[karel]

What happens if you run this command in the terminal: sudo apt update && sudo apt install snapd && sudo snap install gtk-common-themes ?

[Bharath kumar V]

@Markkirby, the error message what I saw/see on the screen is what I have given in my query. I have a screenshot, but I don' t whether I can upload an image here. Because I find there is no such option here.

[Bharath kumar V]

@karel, I have tried the command in the terminal. The installation went on well. Thanks.

[Bharath kumar V]

@karel, can you please explain why I could not do it through "Ubuntu Software Centre"? Thanks.

[karel]

I discussed this topic once with a lead Ubuntu snap developer and he explained to me that snap packages are supposed to install in the Software app with all the correct options pre-selected every time. Sometimes this does not work however. If this isn't a bug then it's possible that you need to update the available software first with the command: sudo apt update because the available software in the Software app was not up-to-date when you tried to install the package.

[karel]

I haven't seen this happen yet in Ubuntu 18.04. In my Ubuntu 18.04 the software in Ubuntu Software is always up-to-date.