Unity Dash Does not Shows any Applications. Searching Applications for ever

Question

I installed the day before a set of packages for GCC-4.8.2 compiled on my machine Ubuntu 12.04. After the installation of the 52 packages I got some broken dependencies with i386 libraries (Multi-Arch) I did not compile at that time as I had compiled the amd64 version. As soon as the Update Manager displayed the red icon (broken packages) I noticed that the Unity Dash was unable to show any applications. I shut down my PC for the night in that state. The following day I fixed all the i386 (Mulyi Arch) libraries. Then the Update Manager was working again, but the Unity Dash is still unable to show any application ...

I tried to purge and re-install unity-lens-files and unity-lens-applications then restarting the PC. That didn't change anything to the Unity Dash behavior. It looks like there is somewhere a bug or some configuration on which it relies is corrupted. Everything else is working fine so far.

Answer 1

Sorry for disturbing people here ... This low tech failure had me on my nerve.

The solution was to clear the software-center hidden folder ~/.cache and to reset unity. This is one of the solution proposed on Dash search gives no result. However in order to be able to restore the cache in case this does not work it is better not to remove it first but to rename it to -bak for exemple:

$ mv ~/.cache/software-center{,-backup}
$ unity --reset &

Or <Alt> <F2> and type unity (to reset not using a terminal). After checking's it's working

$ rm -r ~/.cache/software-center-backup/

Answer 2

I am using Ubuntu 14.10. unity reset option is now deprecated. If software-center cache data caused this issue, by taking a backup & removing the folder should allow unity to function as usual.

$ mv ~/.cache/software-center{,-backup}

then after few seconds, try using the dash again. We should get back the applications listed.

If you are struggling to manually invoke any general apps., press Super + N to open folder and navigate to /usr/share/applications. Here you should find general applications listed.

Once the unity is back, analyse log files in ~/.cache/software-center-backup to understand what went wrong.