Hi

I had not used my computer for about a month, so there was lots of updates which I installed first, then I opened Firefox, checked emails etc with no problems.

Next day when I turned the computer on, I noticed:
# update manager shield missing from bottom toolbar
# update manager would not open
# Firefox would not open
# package manager would not open
# Home/Music/ album art now missing (just got music note), don't know if part of the problems.

What I've tried so far:
# opened software manager, removed Firefox, then reinstalled, still not launching.
# installed Chromium from software manager so would have a working browser to use, but that won't launch either.
# found someone online with same problem (Firefox won't launch), his advice- type Libnss in software manager- then install Libnss tools- worked for him- didn't work for me.

Now I'm stumped, I've only used the terminal a few times when given step by step instructions as I don't understand commands, but will have a go if told what to do.

I have Linux Mint 18 Sarah 64 bit Mate 1.14.1 on my desktop computer.

Any help would be much appreciated, thank you.

First try launching firefox inside a terminal. You will then see the error messages which are otherwise lost. The likeliest cause of the trouble is a lost library which all these applications are supposed to use. In fact, it would probably be worthwhile to launch one or two other problematic programs in your terminal and compare the error messages. If they all mention the same library, you have your culprit! If not, post the errors that FF gave and we'll focus on that.

In general it is not a good idea in Linux to simply copy what someone else did without doing a little on-the-spot diagnosis first. That man probably had had a completely different problem. There are many reasons why a program might not start. Fortunately Linux provides excellent diagnostic tools and methods for narrowing down the cause of a problem.

Hi Hazel

Thanks for your quick response.

I have just typed "firefox" in terminal, no error message appeared, just another line to type into, so I typed "chromium" to find if that browser will launch, and it says "chromium:command not found". Next I typed "package manager" and it says " the program "package" is currently not installed. You can install it by typing: sudo apt install mailagent".

I stopped there, it did not say "package manager", sounds like something else, and obviously "package manager" should still be installed.

Hope I've done this right, what should I try next?

Sorry for slow reply, using Nook hd tablet (no predictive text), one finger typing!

Regards

Bill

So you typed "firefox" and just got another prompt? And chromium isn't found in spite of the fact that you say you have installed it?

Let's try something even more basic. The which command finds other commands for you. So type which firefox and which chromium and see what comes up.

There is no program called "package manager". Mint has a fully featured package manager called synaptic (all members of the Debian family have this) and a simpler Mint-specific one for newbies. Unfortunately I can't remember what that one is called but it certainly isn't "package manager". Program names never consist of more than one word.

"Which firefox" produced: "/usr/bin/firefox"

"Which chromiun" produced nothing, just another prompt.

If I open the menu, click "internet", it shows "chromium web browser" just above "firefox web browser", so I am assuming that it has downloaded ok from software manager, I have pinned a shortcut to the bottom toolbar, but it will not launch from the menu or the shortcut.

I've typed "which synaptic" and got "/usr/sbin/synaptic".

Hope this helps.

Check your spelling. It's chromium as in the metal, not chromiun".
Good. So at least you have a working package manager. What happens when you type "chromium" correctly spelled?

Typing "chromium" (correct spelling) gives "chromium: command not found"

Typing "which chromium" just produced another prompt.

I've gone back in the terminal and found that the original spelling was correct, the mistake was my one finger typing on the nook tablet, sorry.

That's weird! You say that you have both Firefox and Chromium on your menus but it seems that you don't actually have the programs. That would certainly explain why clicking on the menu option doesn't work.

Next thing is to find out what your package manager believes about them. I mean your real package manager, the apt system, not the newbie-friendly front end that Mint supplies (which you say you are also having problems with).

You can use either apt-cache or synaptic for this step. The command sudo apt-cache show firefox should give you all the information about it including whether it is actually installed. Alternatively, if you prefer a graphical interface, sudo synaptic will show you a list of all your installed programs. If you find FF in the "installed" list, click on it and look at its properties. There are several tabs; one gives you a list of all the files included in the package and you can check for the actual presence of some of these.

If apt has really got mixed up about what is installed, there are ways of fixing that, but they are a bit above my pay grade.

I have used "sudo apt-cache show firefox,"

It seems that several versions have shown up, lots of script, but briefly:

# Package: firefox
Version: 59.0.2+linuxmint1+Sylvia
Architecture: amd64
Installed Size: 171880

# Package: firefox
Architecture: amd64
Version: 59.0.2+build1-OubuntuO.16.04.1
Priority: optional

# Package: firefox
Priority: optional
Section: web
Version: 45.0.2+build1-Oubuntu1

Prior to the last update I believe that I had firefox 59.0.1 installed. Please let me know if you want any further details of the script, I can't think of a way to send it other than typing it out line by line

I really appreciate your help with this problem, especially over the Easter period, thank you.

I think only the first of those three entries is relevant as it is the only one to quote an installed size. The other two are listed simply because they are available in the repository. You can confirm that by calling up synaptic, which will give you the information in a nice graphical format. Click on the search button, enter firefox in the search box and see what comes up. If FF-59.0.2 is definitely marked as installed, I would look at its file list. You will see the full path names of all the files, so you can jot down a few of them and check if you can find them on your system.

/usr/bin/firefox is the program that should actually be launched. You don't seem to have this, as which can't find it, but I would still check by looking for it directly. Belt and braces! And look also for /usr/lib/firefox/firefox. That is the actual firefox program (/usr/bin/firefox is just a link to it).

Have just tried entering "sudo apt-cache show chromium", results:

N: Can't select versions from package " chromium " as it is purely virtual
N: No packages found

I don't mean to sidetrack, getting firefox working is the priority, but now that you have shown me the command to use, I thought it would be useful to know if chromium is installed or not, although I have no idea what the response means. According to the software manager, chromium browser is installed. It takes so long to type a message on this little tablet, it might save time later.

It means that there is more than one package that can do the work. "Chromium" covers all of them. Forget about chromium for now. You need to find if there is something wrong with the apt system on your machine.

Hit a snag. Typed "sudo synaptic", response: " [sudo] password for bill ", entered my password, just got a prompt?

Could this be because I can't open synaptic from the menu, although when I typed" which synaptic " it produced "/usr/sbin/synaptic", so why would it not open?

Looking back, both of the other firefox versions do have installed sizes, hidden lower down in the script.

Try it again with the full path: sudo /usr/sbin/synaptic. sudo doesn't always include /sbin and /usr/sbin on its path. It depends how the distro developers chose to build it.

Tried that , results "bash: sudo/usr/sbin/synaptic: no such file or directory