I changed Linux's theme (Ubuntu 16.04 LTS) with gtk3 and now most applications don't work

Hi,

As quickly said in my title, I wanted to have a new theme on my Linux. I used gtk3+ themes I believe such as Flat, and changing icons / dark theme with the gnome tweak tool. However I was using gazebo before, and now that I have changed themes it doesn't seem to work anymore, same goes with pdf files that i can't seem to see once opened. I have no error messages, I even went back to the original theme with the command : dconf reset -f /
I am kind of running out of options, I don't really know how could I fix this, don't hesitate to ask more details if I haven't been clear enough.

Sincerely.

When you went back to the original theme, did things start working properly again?

No, unfortunately it's still not working maybe some config file was changed but I don't know which or where

You could rename your ~/.config and ~/.cache directories, then log out and log back in.

Originally Posted by adatextio I even went back to the original theme with the command : dconf reset -f /

this looks like it's doing much more than just resetting to the default theme.
anyhow you didn't tell us how and what you installed.

Hi, thank you for your answers :
to ondoho :
I believe I followed these instructions to do the theme installation LINK HERE.
to frankbell :
No it didn't help me to launch gazebo still nothing visible.
to dugan :
I'm sorry I don't really understand what should I rename these directories.

Thank you for your time

Those are two hidden directories. .config contains certain configuration information and .cache contains certain cached (temporarily saved) data.

If you rename the existing directories, log out and back in, the OS will create new .config and .cache directories. If everything then works, that tells you that the problem file(s) are in one of those directories. That you renamed the directories means that the data is still present on your hard drive.

If you wish, you can then restore files from the old .config one by one to identify the culprit.

There are other hidden files and directories (dot-filename) that also contain configuration information. They are hidden not because they contain sensitive data, but because user generally doesn't have to mess with them. It's like putting stuff you don't need right now in a closet until you do need it.

You can view the dot-files in your file manager (there's usually a checkbox somewhere on some menu for "show hidden files").

Originally Posted by adatextio I believe I followed these instructions to do the theme installation LINK HERE.

which answer?
as i see it, this is for unity, and pretty old at that. ubuntu went back to gnome a while ago.
even so, it says "Just a warning, not all themes work nicely under unity." - the same can be said for gnome.

and how did you come up with "dconf reset -f /"?