This is a Google Translate from the Chinese DJI forum.. It was posted by an user called Landlord - http://bbs.dji.com/thread-16464-1-1.html - Might be an interesting read for those having issues. Point 1 is interesting..

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Phantom 3 1.2.6/1.2.8 Firmware Update Issues and Resolutions


At DJI we are dedicated to creating the world’s most advanced flying platforms and camera stabilization systems. This dedication extends to ourdesire to provide quality products that meet and exceed the needs of our customers.


Recently however, we have had reports of a number of issues arising from our latest firmware upgrade, specifically upgrading from 1.1.9 to 1.2.8 onthe Phantom 3 Advanced and from 1.1.9 to 1.2.6 on the Phantom 3 Professional. We sincerely apologize for any inconvenience caused and we are pleased to say that after extensive research and over 1000 flights, resolutions are now available. We would also like to extend a special thanks to users who reported the problems to us and assisted us as we worked on fixes.


If you have experienced any issues with your Phantom 3 Advanced or Phantom 3 Professional, please see below. If your issue is not below please let us know and we will work to resolve it as soon as we can.


1. Non-visual live feed image, i.e. a blank screen that appears instead of a camera feed.

Reason: Certain chip pins on the SD card are not connecting properly tothe circuit causing the camera to start up abnormally, making the screen turn black.
Solution: Remove the SD card and re-install it tightly.
Further solution: The camera startup process is being refined to take into account possible connectivity issues with the SD card. If necessary, DJI will repair affected units as quickly as possible.


2. Increased lag and screen flicker.

Reason: The DJI Pilot app is extremely complex, causing it to place highdemands on your mobile device’s processor and power consumption. This is especially true of three functions.
a) Live feed, location map and Flight Route Recording all draw on processing power.
b) When activated, the Video Editor automatically transcodes your live feed and creates your video in real time using your phone’s processor
c) When the remote controller is connected to an iOS device, your iOS device will specifically use a Central Processing Unit (CPU) core to deal with data authentication computation.
All of these functions increase the power consumption of your mobile device, in turn causing its temperature to increase. Most devices will lower processing speed when a temperature threshold is reached, slowing down the app causing lag and flicker.

Suggested solution:
a) Activate hardware decoding on your mobile device in the DJI Pilot app to reduce demands on your mobile device’s CPU.
b) Choose a lower code rate under Image Transmission Quality assmaller files decode more efficiently.
c) Shut down any unused application programs, or activate “Flight Mode”
d) Keep your mobile device in a cool place whenever possible and keep it out of direct sunlight when flying outdoors.

Further solution:
We will continue to optimize the DJI Pilot app, increasing computation efficiency and lowering power consumption to ensure that it always runs smoothly


3. Flickering screen and/or a blank screen during flying.

Reason: When the Phantom is flying at an extended distance, the angle of the antennas is essential to maintain a strong signal.
Solution: Refer to the user manual and adjust the antenna angle.


We would also like to take this chance to share some good news with everyone. Many users have suggested that we provide more versions of the firmware so you can choose which one to use. This is something that we have taken on board, and we are delighted to announce that we will be making that happen as soon as dedicated engineers assess the best possible way to make this available.

In the future, there will be two versions of the firmware for you to choose from, the previous version and the new one. This means if for any reason you are not satisfied with the latest firmware you can revert back to the previous one.

We are constantly working to ensure that our customers are satisfied and will continue to optimize our products and provide the best service we can. If you have raised a problem about your Phantom 3 on the forum and it still has not been resolved, please contact our dedicated customer service team and provide as much detail as possible about your issue. They will be more than happy to help you.

Thank you for your sincere understanding.

DJI

Good find, was there a mention of possible firmware roll back? misinterpretation on my behalf probably! Glad dji have acknowledged the issues.

Philliplloyd20 Posted at 2015-7-1 18:04
Good find, was there a mention of possible firmware roll back? misinterpretation on my behalf probab ...

Think it says they will release 1.1.9 but as version 1.2.9 to maintain visioning.

All LAG problems comes with 1.1.9............. they must work over 1.1.8. not 1.1.9.

thats great

So 1.2.9 is actually a downgrade to 1.1.9, hmm not sure if this will fix SD card issues mentioned in point 1, as this seems an assembly issue to me.

I never remove my sd card , should help with the contacts ..  

Well that explains a lot. Thanks for posting it here Splooge, too bad DJI didn't post this here themselves so that us customers in the West knew they are working on solutions to our problems and not ignoring us.

Down near the bottom of your list - "...increase the SDK support..."

Saw some info yesterday about Ultimate Flight. The author of that app wrote (I guess one could say it was a blog) about some of the problems they have encountered in writing/developing the app. One of them was the observation that they've had several instances of a "fix" that broke something that had already been fixed.

Growing pains - or worse?

yes, they should rollback to 1.1.8 and not to 1.1.9

Caton, scraper?  somebody translate.   thousands of sorties testing!   i suppose they are counting the people who bought the P3 and installed the update.  ie the paying beta testers.

I'm glad I waited and stayed on 1.1.9 now. Phew!

Absolonkort Posted at 2015-7-1 21:55
I'm glad I waited and stayed on 1.1.9 now. Phew!

my pro is still on 1.1.9 also

Are you having lag issues with 1.1.9?  I am running DJI Pilot 1.20, firmware 1.28 on my Samsung S6 edge (recently factory reset so it ONLY has the DJI Pilot APK) and it starts to lag by 5+ seconds after 10 minutes of use...which was better than 5 minutes of use before the factory reset.  I am buying an Nvidia Shield Tablet in hopes that using it solely for the DJI Pilot APK will provide a temporary fix.

ben_m16 Posted at 2015-7-1 18:49
All LAG problems comes with 1.1.9............. they must work over 1.1.8. not 1.1.9.

Yes, the 1.1.8 was the best of all firmware versions.

Kotaix 1 Posted at 2015-7-1 23:15
Yes, the 1.1.8 was the best of all firmware versions.

What did it update over 1.1.6?

So they admit:

1. SD card sockets are defective on some drones.  This can cause the drone to black out mid flight.

2. The version 1.2.6 - 1.2.8 added features that increase processor load that can cause the mobile device to overheat mid flight.

3. DJI is planning to release a rollback strategy.  (Thank you.)

But they don't seem to mention the issue with the VPS.  The VPS is completely broken in 1.2.6 - 1.2.8  What about the VPS issue?

Fulgerite Posted at 2015-7-1 23:42
So they admit:

1. SD card sockets are defective on some drones.  This can cause the drone to black  ...

I have to agree with Fulgerite.   VPS (and other issues!) remain - they are not telling the whole story.

I'm not entirely sure whether this particular rollback strategy is a strategy or a bodge. Long term though its good news they're developing a proper rollback function.

Also this would I assume remove the lens correction they added in 1.2.6 so its anyone's guess if the lens profile now in Lightroom 2015 CC should be applied or not.

Lets hope it brings with it reliable VPS functionality and that they address that problem in 1.3.0!

lasuncion Posted at 2015-7-1 20:53
yes, they should rollback to 1.1.8 and not to 1.1.9

My thoughts exactly

Anyone that wants 1.1.8 as the previous firmware should speak up soon and I think it won't hurt to contact support with a simple polite email regarding this.

I've started a poll here about it, would like to see who else agrees: http://forum.dji.com/thread-23206-1-1.html

phinchman Posted at 2015-7-2 00:21
I have to agree with Fulgerite.   VPS (and other issues!) remain - they are not telling the whole  ...

My VPS worked on 1.1.9. I am guessing a rollback to then will fix it.

I think a rollback to 1.1.8 would also be the best. I had the least issues on the firmware and it was by far the most stable

Thanks Sploodge for the update - appreciated. It would be nice if they provided such updates for their English speaking customers.

Good find

Cheers.

Tahoe_Ed, please chime in on this development and elaborate on what we can be expecting and when.

Thanks

I also translated the link in the first post in this thread via google translator and viewed the entire thread and found that "We are not alone."

When? I'm grounded until the rollback.

I'm worried about the SD card holder pins. If they're defective or break over time, the P3 won't have a long lifetime, and we'll all end up needing to send them back for repairs.

I'm not sure how they managed to screw up something like that, either. That's elementary stuff...

The announcement is released now.

DJI just caught up to Sploodge  ... hehe ...

collinma21@gmai Posted at 2015-7-1 22:43
Are you having lag issues with 1.1.9?  I am running DJI Pilot 1.20, firmware 1.28 on my Samsung S6 e ...

Out of interest, have you tried putting the Phone into Flight Mode before flying?

CapitAn Posted at 2015-7-1 23:22
What did it update over 1.1.6?

My P3P had the 1.1.8 when I bought it.

Why am I apparently the only person whose UAV is working with 1.2.6?

highlanderstudi Posted at 2015-7-7 07:06
Why am I apparently the only person whose UAV is working with 1.2.6?

You're not the only one! I wonder what they're going to be modifying in the "new" firmware....

rob@devgamers.n Posted at 2015-7-1 22:29
my pro is still on 1.1.9 also

Me too

It has glitches too - like the camera booting (if that is what is going on) once in a while. But overall, 1.1.9 works well. Can't speak of the later versions yet - will wait a bit for DJI to get things sorted.

Hopefully DJI will then add a comprehensive CHANGELOG that will tell us why we might benefit from upgrading (from 1.1.9 etc.).

highlanderstudi Posted at 2015-7-7 07:06
Why am I apparently the only person whose UAV is working with 1.2.6?

My P3P flies just FINE on 1.2.6 !!!

Same here guys.....except when I forget to take the lil "remove before flight" foam block on my gimbal LOL

My new P3P and RC are on firmware 1.1.9. Due to the multiple issues reported by other users as to the new firmware 1.2.6 I am very hesitant to upload and possibly wind up destroying my new drone. Consequently I intend on continuing using firmware 1.1.9 until DJI can get their act together. Meantime when I powered up my P3P, RC and DJI Pilot software v 1.2.0 It reflected a warning that the RC, Camera, and copter required an update. QUESTION: Can I ignore the warning and continue using the true and tested firmware 1.1.9???

i own two P3ps and with 1.2.6 one is now blind with no video and the other is just crazy and inconsistent.. Why no replacement for 1.2.6???? I have no idea if and when i will see firmware. Why are we in the dark? With no help.. Not being able to reload or backup is rediculous... For me these are not toys but tools and owning a room full of DJI products i feel betrayed and abused.

Why no current posts in the last couple of weeks... Am i missing something.. Almost six weeks since 1.2.6 released.. And no news.. .?

At least fix the header, rename  so we can reload 1.8.  It worked great!  I waited for machines, then batteries then got taken out by bad firmware??  Anyone got an idea.. Please help... Got jobs to do. I dont know if i have hardware  issues or just a bad load?? It went from dark video to stuttering and then no video.. Tried different pads, setting and even pre chilling in the fridge but now no video at all??? DJI please help.