Good afternoon. Such a problem, hap aс2 router. The zerotire package was installed, version 7.12.1 was installed, updated to 7.13, the router booted normally, there was 40 kilobytes of free space left, I upgrade the roterboard firmware (system RouterBOARD), rebooted and that’s it, the router didn’t boot anymore, nothing, no resets, nothing helped. I tried to reflash with netistall, tried about 10 different versions, ranging from the factory version 6.45.9 to 7.13, none of them want to flash, the device appears in the program, I select the firmware, click install and nothing happens, it says installing and disappears or does not write anything at all. .. Tell me what to do please. Sorry for the crooked language, I am writing through a translator.

The good old "click install and nothing happens" problem. I ran into that already. This might help: https://www.youtube.com/watch?v=-mOGD1-Uv2Y

Thank you, the situation is similar, but it’s not clear why it didn’t want to send and flash from a physical computer, but it worked from a virtual computer. Why does this happen and what caused it?

Netinstall can be very finicky when starting from a windows computer.
You really need to make sure to disable ALL network interfaces except the ethernet one.

Using an old 2008 Linux laptop I've had close to 100% success.

You really need to make sure to disable ALL network interfaces except the ethernet one.

Often times even that doesn't fix it. Other people recommend trying another machine or laptop, some people recommend a VM, I'm in the same camp as well. But next time I will try the Linux version of Netinstall. So far I only needed Netinstall once after a very short power outage. All I got was a bootloop.

I have a similar problem with the exact same router. The only difference is that netinstall sees it and flashes it, but after a reboot the router restarts cyclically. I tried firmware versions 6.49.11, 7.12.1, 7.13. Trying to start the backup bootloader by pressing reset for 1-2 seconds before applying power also does not help. What options are there to revive the device?

Netinstall allows to keep existing configuration. Generally it's good idea not to ... because when boot loops happen, the problem often lies in the config itself.

Another problem might be corrupt or too old routerboot firmware. If it's corrupt, then booting using backup routerboot might help (but backup routerboot is highly likely even older, see next sentence). If it's too old, then routerboot might not be able to boot newer ROS versions. In this case solution is to (net)install as recent version of ROS v6 as possible and hit the routerboot upgrade after device boots. IIRC for booting ROS v7, routerboot has to be newer than 6.47 or something.

And, of course, there's a (small) chance that flash storage is actually broken ... there's no cure for this kind of problem. I've no idea if netinstall detects broken flash.

In my case, the RouterBOOT version was upgraded to version 7.12.1
Flash process - ok. But bootloop after reboot

Same problem here. AC^2 bricked after upgrading RouterBOOT to 7.13.

absence of thorough testing by MT.....

managed to recover. I have a feeling it has something to do with free-hdd-space equal to 0KiB. Can it be that RouterOS is trying to write something to a flash during the bootup? After reset I now have free-hdd-space: 448.0KiB and it just works fine. Both RouterOS 7.13 and RouterBOOT 7.13

absence of thorough testing by MT.....

What brings you this conclusion?

This topic.

This is one of the first test cases testing department should declare.

- upgrade with minimal available free space

And because MT knows the disk space requirements, it's a fail that this led to a full root partition and a boot loop.

managed to recover. I have a feeling it has something to do with free-hdd-space equal to 0KiB. Can it be that RouterOS is trying to write something to a flash during the bootup? After reset I now have free-hdd-space: 448.0KiB and it just works fine. Both RouterOS 7.13 and RouterBOOT 7.13

Is there an algorithm for how to restore?

Apart from netinstall, is there way to downgrade from 7.13?

What I observed last night after few hours,
1. update to 7.13 with old wireless package and zerotier. Initially worked but afterward when reboot, not working.
2. I try netinstall but cannot find the device (may be I did not do the right reset
3. anyway, seems to have a proper reset this morning, the router is online again. Missing the router password but configuration seems to retain. I delete zerotier and still working after several reboot

The next question is to downgrade to 7.12.1 o r even version 6

Please advise.

Finally I use a very old laptop > 10 years with Windows XP to complete the netinstall procedure

Perhaps hAP ac2 may be the time to fade out

However, I still cannot make my AX3 work well for my requirememt

+1 dead AC2 that ran 7.13+ww2 happily for a month, minimal free space became less although I didn't have anything configured to spend it, and one nice day it died, most probably to 0 bytes left on storage, and doesn't boot to working state anymore.
I can probably netinstall it to 7.13+wireless, but question remains: although 7.13+ww2 is doable on AC2, does Mikrotik see it as a sane thing to do?

+1 dead AC2 that ran 7.13+ww2 happily for a month,

Quite hard to believe. 7.13 was only released on dec 15th ???
Unless you are referring to beta version ?
Did you upgrade to stable already ?

... minimal free space became less although I didn't have anything configured to spend it, and one nice day it died, most probably to 0 bytes left on storage, and doesn't boot to working state anymore.

I would suggest to netinstall and start from a CLEAN config only having qcom-ac added as package and minimal needed config. Everything which you can offload to another device, move it away !
AC2 was already known for very tight storage space, this new feature with wave2 drivers made space even more restricted.

I can probably netinstall it to 7.13+wireless, but question remains: although 7.13+ww2 is doable on AC2, does Mikrotik see it as a sane thing to do?

Do you think they would have released that option if they didn't believe themselves it was sane to do ? Spend all that effort on making this option available ?

It's not only AC2, also cAP AC, cAP XL AC, wAP AC, ... quite a lot of devices getting a second chance in their lifecycle.
Economically maybe not the best decision from Mikrotik (they loose quite a bit of possible replacement sales) but from a user support standpoint simply brilliant !
My view...

I have at least 3 hAP ac 2 devices still working. But the amount of free space is really frighteningly small So what should I do? Upload 7.12.1 via netinstall? Or wait for a reaction from the developers? I don’t really want to find out in the morning that I have minus 3 devices in bootloop

cAP AC, exact same resource restriction as AC2.
This one has qcom-ac package added but is acting as a simple AP, nothing more.

Running for 11 days already.

[xyz@<somewhere>-cAPAC] /system/resource> print
uptime: 1w4d2h19m10s
version: 7.13 (stable)
build-time: Dec/14/2023 09:24:08
factory-software: 6.44
free-memory: 31.5MiB
total-memory: 128.0MiB
cpu: ARM
cpu-count: 4
cpu-frequency: 672MHz
cpu-load: 3%
free-hdd-space: 692.0KiB
total-hdd-space: 15.2MiB
write-sect-since-reboot: 3500
write-sect-total: 371047
architecture-name: arm
board-name: cAP ac
platform: MikroTik

I have at least 3 hAP ac 2 devices still working. But the amount of free space is really frighteningly small

So what should I do? Upload 7.12.1 via netinstall? Or wait for a reaction from the developers? I don’t really want to find out in the morning that I have minus 3 devices in bootloop

And with 7.12.1 remaining space was that much more ? Little space on itself is not a problem. Zero space is.
You can always downgrade but it may be possible you will have to setup wifi interfaces completely new again. Never tried that path myself.
I've seen reports of users stopping upgrade path for AC2 devices to maximum 7.12.1, they don't move further to 7.13.

Maybe something will be done in future about the monolithic nature of the RouterOS package like it used to be be in earlier ROS6 days. That would make it possible to select which packages you use and which not (hence freeing space by omitting unused features).
But make no mistake here, that path as never been confirmed by MT staff, it's just some hoping from users.

Is there an algorithm for how to restore?

Hold reset on power-on and keep it for 30secs.

Mikrotik could potentially strip out routing daemons from the main bundle. This would save some space.

On the too small hdd-space (flash memory) in the hAP ac2, just a tought, never tried, but is "etherboot" a potential path to boot from a larger image, or is this only usable for Netinstall, not for booting up?

While reading about Protected Routerboot procedures in the HELP section ... "reformat-hold-button" : RouterOS, all of its files and configuration is completely and irreversibly erased by nand re-format;.
Hmmmm, nand reformat: lets hope it would not erase the license!. (Like the e in Routerboot: e = format storage = Destroys all data on the NAND, including RouterOS configuration and license)