Ubuntu mate Panel disappeared

[vaah]

I've just installed ubuntu mate 19.04, coming from mate 16.04. I upgraded to 19.04 because I recently had intermittent problem with error saying "Attempt to read or write outside of disk 'hd0' ". I did some research and someone suggest that the boot partition should be GPT not MBR so I wiped my boot drive. then I set the partition table to GPT. So after19.04 installation, all is well. since /home is separated on other drive, all my old configs are retained.

I see my mate panel is cluttered and decided to reset it, by right click menu, reset panel. after that the panel is gone forever. Since this is freshly installed, i decided to reinstall again. But menu is still gone...I tried typing mate-panel --reset and replace, still nothing. I hope someone can help me..

[lah7]

Welcome! Not to worry, to "reset" the panel, use MATE Tweak to choose a different panel, then set it back to the one you'd like.

There are some technical differences between 16.04 and 19.04's panels, so MATE Tweak will recreate the panel with the necessary updates.

You should be able to press ALT + F2 to open the Run dialog, and type:

mate-tweak

If the Run dialog doesn't appear, press CTRL + ALT + F1 and login to the console. Type:

DISPLAY=:0 mate-tweak

Then return to the graphical session with CTRL + ALT + F7

[vaah]

@lah7 Thanks for the reply. So because i was guessing it may be caused by old config left in my /home directory. I decided to install ubuntu mate again but i don't specify the /home partition during installation so this time it should be really fresh install. But the panel still doesn't work. The rectangular block panel at the top and bottom now appears but both only show solid black, no menu, no date and time, no notification applets that shows network. Real nothing. What could be wrong?

This is so strange, actually i forgot to mention another factor causing me to decide to upgrade. When i was still using 16.04, the application (e.g. caja or firefox) would freeze shortly after I login. And i think the problem still persist even after i install 18.04 or 19.04.. do you know how to solve this problem?

[lah7]

How much memory (RAM) does your system have? Freezing could be a sign of running out of memory, but if there is plenty of RAM (and swap), it could be down to other factors.

Are you using a 32-bit or 64-bit installation? It seems uncommon for a fresh install to be unable to display any panel. Are they totally black or just blank (grey)? Are you able to right click and add applets?

If you haven't already, it may be good to update the system to the latest packages. If you have a wired connection and can open a terminal (or console), this ought to ensure it's up-to-date:

sudo apt dist-upgrade
reboot

[vaah]

Ram is 8gb, 64bit. Panel shows solid black, i can't add any applet since if i right click on it, nothing comes up.

Last night i tried official ubuntu 18.04 and it kinda works. Then i decided, just now i decided to reinstall ubuntu mate 18.04 this time. But after grub screen. The following error keeps popping up.

Initially that error is what prompted me to ditch my 16.04 and install latest version of ubuntu mate. It seems that error came back.. i already set my boot ssd as GPT table.

[lah7]

How large is your SSD? It's either a hardware issue (drive going faulty, or a defective SATA cable) or the drive is being limited by the hardware - i.e. the way it is partitioned.

The error message is being produced by GRUB, the bootloader.

To rule out the SSD being the issue - try booting a live session of Ubuntu MATE and open Disks. From here, you can perform an extended S.M.A.R.T. test.

Screenshot of the menu - but as it's from a virtual machine, it's greyed out. On physical hardware the option should be highlighted, unless S.M.A.R.T. is turned off in the BIOS settings.

---

Since you say your /home is on another drive, presumably you'd be happy to start fresh on the SSD?

If so, use GParted and create a new partition table, which will destroy any data on that disk and wipe the bootloader (GRUB).

Create a new gpt partition table, then proceed to install Ubuntu MATE (18.04 LTS or 19.04) again, but use Something else to create the partitions like so:

If it's booted in BIOS mode:

Drive	Type	Mount Point	Size
/dev/sda1	ext4	/boot	500 MB
/dev/sda2	ext4	/	(Remainder of the drive)
/dev/sdb1	ext4	/home	(Other drive)

If it's booted in UEFI mode:

Drive	Type	Mount Point	Size
/dev/sda1	EFI		200 MB
/dev/sda2	ext4	/boot	500 MB
/dev/sda3	ext4	/	(Remainder of the drive)
/dev/sdb1	ext4	/home	(Other drive)

Welcome can tell you which mode under Installation Help → Installation Preparations in a blue stripe.

The bootloader should be installed to /dev/sda. See if having a boot partition suppresses that error message, and if the disappearing panel situation improves.

[vaah]

SSD is only 120GB. The following image is the S.M.A.R.T test result.

Yes, my /home is on another separate drive so i can save it when problem like this arise. I already set the partition table to GPT, should I redo it again?

[vaah]

Hi @lah7, so I am a bit lost here, where can I find

Welcome can tell you which mode under Installation Help → Installation Preparations in a blue stripe.

?

[lah7]

I already set the partition table to GPT, should I redo it again?

I'd suggest doing it again via GParted. A fresh partition table for a fresh set of partitions. This clears the bootloader (GRUB) too.

---

Ubuntu MATE Welcome is pre-installed and can be found in the menu like so:

→ →

[vaah]

Thanks, I confirmed my system is running in BIOS mode. I have followed your instruction, this time around I think it works fine. The panel works, and so far no freezing after login. So I don't need to execute sudo service lightdm restart like before.

I've set the /boot partition to 500mb. I tried updated the kernel using software updater, but it complained for lack of space in /boot if I set it to 200mb like you said.

Thanks for the detailed help!! you really helped me.

I'll report back if the problem comes back again.

[lah7]

No problem! My bad for suggesting 200 MB, I didn't really know the best size since I generally remove old kernels. I'll amend the post for others following this.

I did have second thoughts that an MBR partition table would have the best compatibility in BIOS mode, but GRUB can happily use GPT. It's working with a smaller partition (/boot) at the start so it seems all good.