Let me be clear: before the upgrade, each bridge had its own MAC address. After the upgrade, there were MAC address conflicts because some of the bridges had the same MAC address. This should never happen. This was on FACTORY DEFAULT firmware and settings.
The ping tool is broken and has been for many versions - I only noticed this tonight. The “timeout” option doesn’t change the ping timeout but rather the interval between pings. So this is either a bug or a badly labelled “ping interval” option. However timeout is a crucial parameter for any ping tool.
[mkadm@MikroTik] > /file print
NAME TYPE SIZE CREATION-TIME
0 flash directory feb/09/2018 20:46:43
1 flash/pub directory feb/09/2018 20:46:43
2 flash/skins directory feb/09/2018 20:46:43
[mkadm@MikroTik] >
/system package print
[mkadm@MikroTik] > /system package print
Flags: X - disabled
NAME VERSION SCHEDULED
0 routeros-smips 6.41.1
1 system 6.41.1
2 X ipv6 6.41.1
3 wireless 6.41.1
4 X hotspot 6.41.1
5 dhcp 6.41.1
6 X mpls 6.41.1
7 routing 6.41.1
8 X ppp 6.41.1
9 security 6.41.1
10 advanced-tools 6.41.1
[mkadm@MikroTik] > [/quote]
And the relevant portion from /system resource printuptime: 16h14m40s
version: 6.41.1 (stable)
build-time: Jan/30/2018 10:26:14
free-memory: 6.0MiB
total-memory: 32.0MiB
cpu: MIPS 24Kc V7.4
cpu-count: 1
cpu-frequency: 650MHz
cpu-load: 9%
free-hdd-space: 7.0MiB
total-hdd-space: 16.0MiB
write-sect-since-reboot: 36352
write-sect-total: 39081061
bad-blocks: 0%
architecture-name: smips
board-name: hAP lite
platform: MikroTik
Lakis, zervan, AntonReviakin - Please contact support@mikrotik.com regarding this issue. I assume that downgrade to 6.41.1 fix the problem and after upgrade to 6.41.2 again shows the same problem.
GreySer - What do you see on serial console? Did you try to Netinstall device?
jackx - If you did not have admin-mac configured, then bridge uses MAC address of first interface recognized by RouterOS. MAC can change between reboots, etc. I assume that downgrade to 6.41.1 fix the problem and after upgrade to 6.41.2 again shows the same problem?
mstead - This topic is created to find problems which were not in RouterOS in 6.41.1 and are in 6.41.2. Have you contacted support regarding this problem? We are not aware about such problem. Write to support@mikrotik.com regarding this problem.
i4ko - Have you had other RouterOS packages installed on the device in the past? If you reboot router is space freed up?
Thanks, it’s works. In virtual WLAN dropdown “VLAN Mode” select “no tag” and reconnecting to both interfaces 
Just now upgraded my wAP AC from 6.41 to 6.41.2. With my MacBook Air '15 RX/TX was 585/526, became nearly 270/270.
P.S. On 6.42 results are much worse.
And the relevant portion from /system resource printuptime: 16h14m40s
version: 6.41.1 (stable)
build-time: Jan/30/2018 10:26:14
free-memory: 6.0MiB
total-memory: 32.0MiB
cpu: MIPS 24Kc V7.4
cpu-count: 1
cpu-frequency: 650MHz
cpu-load: 9%
free-hdd-space: 7.0MiB
total-hdd-space: 16.0MiB
write-sect-since-reboot: 36352
write-sect-total: 39081061
bad-blocks: 0%
architecture-name: smips
board-name: hAP lite
platform: MikroTik
[/quote]
Think only solution will be to export config, save this off the router, then use netinstall with 6.41.2 and import config again
Hi,
RB750Gr3 went to bootloap 
I upgraded from 6.41.1, routerboard 6.41.1. I did it via System → packages → check for updates.
I managed to fix it with, however I am not sure what was the solution-trigger:
- poweroff
- press reset button, power on
- keep the reset button pressed for 300 seconds (I found this somewhere on this forum)
- poweroff
- do the Netinstall procedure. I used Netinstall v6.38.5. (for some reason 6.41.1 didnt work)
- I loaded 6.38.5 Main package,
- it looked like it didnt work but after some time mikrotik beeped and started working.
upgrade from 6.38.5 to 6.41.1
It has been working for 2 days without problem.
Cheers, good luck
I did an upgrad of RB750Gr3 from 6.41 to 6.41.2 - no problems.
Mikhail73 - Please send supout file from your router to support@mikrotik.com. In best case scenario provide two files - one from 6.41.2 and one from 6.41.1 where everything works just fine. This version does not have any wireless fixes;
CZFan - Does reboot free up some space on your router?
eifLZ9D8zSwW - You did - launch backup booter and reset router and bootloader configuration and then Netinstalled router. You could just skip the first part. However, if you had protected bootloader enabled (disabled reset button), then yes - you could not Netinstall router in any other way:
https://wiki.mikrotik.com/wiki/Manual:RouterBOARD_settings#Protected_bootloader
We do recommend to use protected bootloader only if you really need it and are aware how to recover device in case something goes wrong. If you simply decide to enable this feature without actually knowing what it does, most likely you will not be able to recover unit when something goes wrong and in the end will want to return device for warranty repair. However, there is no actual problem with the router.
No and No
What I noticed is that config backup usually used to take shy of 500kb. After the 6.41.1 upgrade, the config backup right now takes shy of 700kb, and there isn’t that much config on them either - address lists with about 940 IPs total (some of it is dynamic entries), 630 static dns entries, and 1 script that has 30 lines.
Some of the device had issues updating to 6.41.1 in the first place as well - they did not update via winbox, but I was able to upload the file and reboot them and they took it (which was unusual - normally it worked the other way around). It seems my last option is netupdate but these are all at remote sites, so not easy to schedule and do and I would like to avoid it. Would downgrade to 6.39.3 and upgrade to 6.41.2 directly if it wasn’t for bridge config changes.
i4ko - Most likely you will need to re-install devices by using Netinstall. However, I recommend that you send supout file from one of your routers to support. We might see in supout file what is filling up the space.
Hi.
I just upgrade my RB750Gr3 to version 6.41.2, and The Dude 6.41.2 server (on RB750Gr3) and the surprise when I try to connect to this system with The Dude client (other times the application itself upgrades downloading directly from MikroTik) is that NOT WORKS. More accurately, the client cannot connect the server because The client 6.41.2 WAS NOT RELEASED YET, and the applicaion complete DOES NOT WORK.
I also try to downgrade to 6.41.1, but the router does not accept it.
Why MikrotiK release only partiallly his software, making impossible the management? I don’t understand nothing.
I hope that Mikrotik releases quickly the new client. At a moment, more than 250 devices of my network cannot be managed. It is a very strange thing.
Best regards.
Miguel
P.D. NOTE: I just made the downgrade from 6.41.2 to 6.41.1. This was an mistake from my part. Sorry. I will expect MikroTik releases all needed sofware before trying to upgrade.
Regards. M.
After upgrading from version 6.39.3 [BugFix] to 6.41.1 and then to 6.41.2, my device [RB751U-2HnD] presented wireless connectivity problems.
I also upgraded the firmware, leaving it equivalent to the ROS.
The causes of the problem could not be identified in the logs.
Even after resetting and redoing all the settings one by one, it was not possible to keep the wireless connection stable.
Upgraded all devices from 6.41.1 to 6.41.2.
Went well, but then after some time my CRS317 lost management DHCP client lease from my CCR1009 (log message via serial on 317 indicates lost lease). Using trunked VLANS.
Haven’t noticed any other devices losing connectivity yet.
edit: Other traffic was still being switched normally. Noticed I was still on 6.41.1 routerboard firmware on the 317. Updated the firmware via serial console (couldn’t connect via MAC either) and rebooted. Connectivity restored via IP and MAC winbox. Will reply again if connectivity lost.
rmonteiraum - Please send supout file from your device to support@mikrotik.com. Send two supout files - one from old version where everything is working properly and one from latest version where it is not. Generate file after you have experienced disconnects;
Can’t connect to Dude server after upgrade.
Dude client update stopped with error “bad http response from cloud”.
Dude server is on router os 6.41.2.
[quote=glat post_id=641703 time=1518275303 user_id=74586]
[quote=facubertran post_id=641682 time=1518264788 user_id=93506]
[quote=lisek post_id=641489 time=1518187833 user_id=114897]
Hi this ver not work in Windows system. Do not download from mikrotik.com. Info from Dude client:
bad http response from cloud
[/quote]
Hi, could you solve the problem?
[/quote]
There’s no way to workaround the bug. We need a new RouterOS release or the dude client 6.41.2 which is not available now. I suspect it’s not available because they know it’s bugged and so last resource is to wait for next RouterOS release. Hope soon.
[/quote]
Hm. I just change version number in standart download link https://download2.mikrotik.com/routeros/6.41.2/dude-install-6.41.2.exe and download dude-client. Looks like it work.
Please write more detailed what kind of wireless connectivity problems you see.
Ova for chr - 404 not found..
https://www.mikrotik.com/chr-6.41.2.ova
Isn’t anyone from the team checking this basics stuff? We always have to report such trivial issues.