There has been a number of issue with the Mavic Pro disconnecting from the remote controller or DJI Go 4 app. It turned out that the micro SD card in the quadcopter was causing the Mavic Pro disconnects.  Most Mavic pilots will remove the SD Card from the Mavic and plug it into an SD card reader and copy across video etc onto their computer.  However the card can become damaged physically or the file system can become corrupt on the card.

Perhaps the card has been used for something else and has other files and folders on it and when it is back in the Mavic, it causes an issue when you try to record to it. The SD card may still work but it is not perfect and is causing an interference when back in the Mavic.

Take out the micro SD card and try flying and see if you still get disconnects. If you don’t get a disconnect, do a full format of the SD card in a Windows computer.  If it is still causing disconnects after the format,  then replace the card with the DJI recommended SanDisk Extreme micro SD Card 64 GB.

Why are you stating all these posts as facts when they are not true?  I have been flying for years and never experienced any of the causes you mention for disconnects.  The remote signal has nothing to do with the SD card.  

You have posted 7 posts, all on the same subject, and all with wrong or unrelated information about why disconnects occur, which in 99% of cases, is simpley poor signal due to external radio interference, long distance, or poor orientation of the remote antenna.  

Ian
https://www.youtube.com/IaninLondon

Pardzfilm, where is your evidence or source for this unbelievable claim?

Disconnection between the AC and RC is caused by obstructions in the environment, interference from WiFi sources and electromagnetism in the environment and more basic issues like a loose cable or flying too far away. The SD card malfunctioning may lead to files being corrupted but will never cause an RC or app disconnection. I appreciate the effort you a have taken to create a multitude of tips on what must be nearly 20 different threads now but do ensure that you yourself know what you are advising on. Unlike most forum users who have been flying for years, there are some that are new to the hobby like yourself who will read your posts and act on them. If the information you give out is inaccurate it may lead to bigger issues down the line and even flyers crashing by being misadvised.  

I am a first timer

A J Posted at 4-14 01:08
Disconnection between the AC and RC is caused by obstructions in the environment, interference from WiFi sources and electromagnetism in the environment and more basic issues like a loose cable or flying too far away. The SD card malfunctioning may lead to files being corrupted but will never cause an RC or app disconnection. I appreciate the effort you a have taken to create a multitude of tips on what must be nearly 20 different threads now but do ensure that you yourself know what you are advising on. Unlike most forum users who have been flying for years, there are some that are new to the hobby like yourself who will read your posts and act on them. If the information you give out is inaccurate it may lead to bigger issues down the line and even flyers crashing by being misadvised.

Thanks sir

PardzFilm Posted at 4-14 01:53
I am a first timer

Then read the Manual a few times.
Posting nonsense like you have been doing do not help anyone.
There are people which come here looking for advice and help and they do not deserve this BS.

Really? It doesn't make sense

PardzFilm Posted at 4-14 01:53
I am a first timer

Many beginners visit this forum to seek advice from DJI and experienced pilots.

As a 'first timer' it might be easier to sit back and learn instead of cutting and pasting poor advice (crap) and then go fly to know what you are talking about

PardzFilm Posted at 4-14 01:53
I am a first timer

Read your manual. I don't see any drone avatars under your profile

Are you even flying drones or just trolling for points or are you here to just state untrue facts?

Woe Posted at 4-14 08:09
Read your manual. I don't see any drone avatars under your profile

Are you even flying drones or just trolling for points or are you here to just state untrue facts?

Woe and others,
I will ignore his posts in future,
He seems to be attention seeking.

AlansDronePics Posted at 4-14 08:53
Woe and others,
I will ignore his posts in future,
He seems to be attention seeking.

Agreed

Seems logical and all the replies to this agree that a corrupt SD card cannot cause disconnection problems. I feel the same way. Except, I experienced this very same issue yesterday with my M2P. Had my normal Lexar 64GB card installed, have used this same card many, many times in this drone. Powered on drone after powering on smart controller. Connection kept dropping and display showed many strange errors like IMU error, cannot take off. I removed the SD card and restarted, switching to internal storage. The problem went away. I tried a Sandisk 64GB card, and there was no issue. Tried the original Lexar 64GB, and the issue came back. I tried formatting it in the drone and still had the issue. I know this sounds like nonsense, it's not. I am not a super-experienced pilot, but I have at least a couple hundred hours flown. I am familiar with most issues and know how to fix them. I guess it's possible a corrupt card messes with the software or maybe creates radio interference. I don't know where the OP posted in other threads, just found this one on Google, but I can at least confirm this issue exists and is not some newbie mistake looking for attention.

Wellsi Posted at 2019-4-13 22:47
Why are you stating all these posts as facts when they are not true?  I have been flying for years and never experienced any of the causes you mention for disconnects.  The remote signal has nothing to do with the SD card.  

You have posted 7 posts, all on the same subject, and all with wrong or unrelated information about why disconnects occur, which in 99% of cases, is simpley poor signal due to external radio interference, long distance, or poor orientation of the remote antenna.  

Totally not true at all. I am sitting here, right now with my mavic mini. It ABSOLUTELY IS the SD causing the remote not to connect. When I try to connect with the SD card inserted, it WILL NOT connect. If I try with the SD card removed, it connects right away! Not only that, but if I connect without the SD card, THEN insert it? It DISCONNECTS AGAIN! It IS THE SD CARD..... Want a video of it happening in real time? I wasted a bunch of time NOT checking the SD card based on your advice. UGH. Wish I wouldn't of listened to your "The remote signal has nothing to do with the SD card" comment..... Maddening. Yes, it does apparently....It will fly without an SD card, it will not fly with one. That's it. Somehow,  It's the card. Period

Bioluminous Posted at 2020-5-16 10:57
Seems logical and all the replies to this agree that a corrupt SD card cannot cause disconnection problems. I feel the same way. Except, I experienced this very same issue yesterday with my M2P. Had my normal Lexar 64GB card installed, have used this same card many, many times in this drone. Powered on drone after powering on smart controller. Connection kept dropping and display showed many strange errors like IMU error, cannot take off. I removed the SD card and restarted, switching to internal storage. The problem went away. I tried a Sandisk 64GB card, and there was no issue. Tried the original Lexar 64GB, and the issue came back. I tried formatting it in the drone and still had the issue. I know this sounds like nonsense, it's not. I am not a super-experienced pilot, but I have at least a couple hundred hours flown. I am familiar with most issues and know how to fix them. I guess it's possible a corrupt card messes with the software or maybe creates radio interference. I don't know where the OP posted in other threads, just found this one on Google, but I can at least confirm this issue exists and is not some newbie mistake looking for attention.

If I have an SD card in the drone, it will not connect at all, If I have no SD card, it fly's no problem. Every, single time. It IS the SD card somehow.

Wilkie Posted at 1-29 08:30
If I have an SD card in the drone, it will not connect at all, If I have no SD card, it fly's no problem. Every, single time. It IS the SD card somehow.

Ever thought of getting a better SD cad or replacing the one you have?

1. What brand and model of SD card?  
2. Did you try formatting it, or a new SD card?
3. Also is the  aircraft & controller updated with latest FW?

Hopefully OP and others with similar issue can report back on the above.

A fix that worked for me is to place the card in an adaptor put it in a camera, mine was a Fuji, but make doesnt matter, format it and put it back in the drone. It started working. This was discussed by an youtuber called Erik Thureson. Big thanks to him.

TBH I never thought this would be true, but I must admit I too have been plagued once with this issue. I have a 128GB card Sandisk Ultra (it's one of the proper cards to use according to DJI) and the day before I experienced loss of RC communication (even at 2-3m) I did transfer some files from my laptop onto the card to be saved on another laptop. So I used the card as a USB thumb drive to transfer files to another laptop. I didn't remove the files I had stored on the root of the card after the transfer but just continued to fly with it like that.
I had a Mavic Mini I used this card in and this particular day the Mini just lost RC communication at 200m distance (luckily it did RTH) and at 3m while trying to do some video's on a beach. It would disconnect and not reconnect. I would have to restart the RC and then could connect again. It happened 3 times that day even after I restarted my phone and the drone and RC. UNTIL I removed the card, formatted it and flew fine ever since. So MAYBE the card got corrupted, drone firmware tries to access the card and for some reason gets the drone confused and looses connection. Just a guess.
Since that day I'm often offloading my files and formatting the card in the drone and never had an issue since.

doglaboi Posted at 5-10 10:56
TBH I never thought this would be true, but I must admit I too have been plagued once with this issue. I have a 128GB card Sandisk Ultra (it's one of the proper cards to use according to DJI) and the day before I experienced loss of RC communication (even at 2-3m) I did transfer some files from my laptop onto the card to be saved on another laptop. So I used the card as a USB thumb drive to transfer files to another laptop. I didn't remove the files I had stored on the root of the card after the transfer but just continued to fly with it like that.
I had a Mavic Mini I used this card in and this particular day the Mini just lost RC communication at 200m distance (luckily it did RTH) and at 3m while trying to do some video's on a beach. It would disconnect and not reconnect. I would have to restart the RC and then could connect again. It happened 3 times that day even after I restarted my phone and the drone and RC. UNTIL I removed the card, formatted it and flew fine ever since. So MAYBE the card got corrupted, drone firmware tries to access the card and for some reason gets the drone confused and looses connection. Just a guess.
Since that day I'm often offloading my files and formatting the card in the drone and never had an issue since.

The Sandisk Ultra cards are on the borderline of being too slow, use them for something else and get a Sandisk Extreme card. It will work just fine.

Geebax Posted at 5-10 14:55
The Sandisk Ultra cards are on the borderline of being too slow, use them for something else and get a Sandisk Extreme card. It will work just fine.

Yeah I just pulled out the card just to be sure and is IS a SanDisk Extreme V30 A2
This is the SD card I have

So technically I should be fine right?

doglaboi Posted at 5-11 02:53
Yeah I just pulled out the card just to be sure and is IS a SanDisk Extreme V30 A2
This is the SD card I have

Yea that microSD card is recommended and great to use.  I have a few and it's been excellent in my A2 and A2S.

A file or something probably got corrupted when you had your earlier issue but luckily resolved after formatting. MicroSD cards can go bad which is rare, or if you accidentally exposed it to a magnet or moisture.

doglaboi Posted at 5-11 02:53
Yeah I just pulled out the card just to be sure and is IS a SanDisk Extreme V30 A2
This is the SD card I have

Yes, that is a good card to use.

I wonder if I should just buy a smaller capacity card since I won't ever have soo much content on it (offloading often because if the card fails or drone lost you will loose all content too).
I'll just put in a 32 or 64GB card in it.

Same problem, seems to have been resolved by simply renaming the old folder and letting the drone create a new media folder.

Wellsi Posted at 2019-4-13 22:47
Why are you stating all these posts as facts when they are not true?  I have been flying for years and never experienced any of the causes you mention for disconnects.  The remote signal has nothing to do with the SD card.  

You have posted 7 posts, all on the same subject, and all with wrong or unrelated information about why disconnects occur, which in 99% of cases, is simpley poor signal due to external radio interference, long distance, or poor orientation of the remote antenna.  

This is a couple of years old. But what a dick head reply to this post. I'm a commercial operator , and today had awful connection issues with my mp2. It was cutting out just feet away from me, and then I was unable to change the aperture or even press record on the smart controller. Everything updated , then I resorted to a full factory reset. Same issue was happening. Switched at the micro SD card and no issues at all. I wish I tried this first. No idea as to why it would happen this way?

I have tried the mentioned solution above in the comments. But, I have also tried:
1. A different SD card. Sometimes, I believe the SD card itself can be corrupted, which can cause problems with the videos that are stored on it.
2. Formated the SD card. That erased all of the data on the card, but it may also fix any corruption that is present.
3. Updated the firmware of my drone. Sometimes, firmware updates can fix bugs that can cause problems with videos.

What else should I try next to resolve the issue?

mark11111111 Posted at 8-22 03:45
I have tried the mentioned solution above in the comments. But, I have also tried:
1. A different SD card. Sometimes, I believe the SD card itself can be corrupted, which can cause problems with the videos that are stored on it.
2. Formated the SD card. That erased all of the data on the card, but it may also fix any corruption that is present.

Hello there. May I know what is the issue with your drone and what drone are you using?