Happen to me yesterday  - Everything was working perfectly on my Mini2 and 2S / Lenovo TB-8504F  Android 7.1.1  -
I got a message "New version available"  _Mastershots, Hyperlapse and Focus Track are now available on DJI mavic 3   etc.  (I have Mini2 and 2S)   
It WOULD NOT UPDATE. got this message  "There was a problem parsing the package"
So I UNINSTALLED the DJI Fly App,  and Installed The New One 1.5.4.  (not sure what I had,  it was only a month old)
It would open for 5 sec with no camera image and close for 10 sec continuously.  
I tried un-installing and re-installing 3 time it still WILL NOT WORK.  -

I did install "Litchi Beta" before this and THAT WORKS (haven't flown it though).  

DO NOT UPDATE !!!!!!!!!!!!!!!!!
the DJI FLY APP to 1.5.4
Until you VERIFY tablet or phone is COMPATIBLE with the UPDATE.
It SHOULD be a BOLD WARNING before you do it.
I just found out my Android Tablet IS NOT SUPPORTED
NO ANDROID TABLET is supported!!
And my Phone is not supported.
So I have to go out and buy a new phone or new I-Pad (I have all Android and do not want I-Pad anything) if I want to fly my NEW Mini2 or NEW 2S,  

Hello there BuzzCheeze. I am sorry for the trouble this has caused and thank you for reaching out. Kindly please try using a different recommended mobile device for the DJI Fly application to see if the issue will persist? Upon checking the said mobile device ( Lenovo TB-8504F  Android 7.1.1 ) that your are using on the DJI Fly application. I am sorry to say that the said mobile device is not recommended for the said DJI application. DJI would suggest using a recommended mobile device for the DJI Fly application for compatibility and reliability purposes. There is a possibility that the Lenovo TB-8504F  Android 7.1.1 will be able to work before on the DJI Fly application. But however, since it's not yet optimized with the said application we cannot guaranteed if it will work all the time and if it will be able to run all the functions of the DJI Fly application while using it. For reference I will post a link where in you can check the recommended mobile devices for the DJI Fly application ( https://www.dji.com/downloads/djiapp/dji-fly ). Thank you.

BuzzCheeze Posted at 1-6 11:36
DO NOT UPDATE !!!!!!!!!!!!!!!!!
the DJI FLY APP to 1.5.4
Until you VERIFY tablet or phone is COMPATIBLE with the UPDATE.

Hi, there. Sorry to hear about the trouble you've encountered. Could you tell me the model of the phone you're using now? And please reinstall the latest version of the DJI Fly via our official website. If the problem persists, please feel free to contact us.
https://www.dji.com/downloads/djiapp/dji-fly

DJI Stephen Posted at 1-6 19:30
Hello there BuzzCheeze. I am sorry for the trouble this has caused and thank you for reaching out. Kindly please try using a different recommended mobile device for the DJI Fly application to see if the issue will persist? Upon checking the said mobile device ( Lenovo TB-8504F  Android 7.1.1 ) that your are using on the DJI Fly application. I am sorry to say that the said mobile device is not recommended for the said DJI application. DJI would suggest using a recommended mobile device for the DJI Fly application for compatibility and reliability purposes. There is a possibility that the Lenovo TB-8504F  Android 7.1.1 will be able to work before on the DJI Fly application. But however, since it's not yet optimized with the said application we cannot guaranteed if it will work all the time and if it will be able to run all the functions of the DJI Fly application while using it. For reference I will post a link where in you can check the recommended mobile devices for the DJI Fly application ( https://www.dji.com/downloads/djiapp/dji-fly ). Thank you.

Yes - I now know my tablet is not on the list - no android tablet is on the list.
I did not know that by accepting the popup offer to update the FLY app on my tablet, it would crash on the tablet I was using, or I never would have updated the app.
I think the pop-up should WARN PEOPLE
before they update
out of courtesy to their customers. I WOULD
I found out the WRONG WAY, I think.

Probably should add
"Will crash on every android tablet"

DJI Gamora Posted at 1-6 20:18
Hi, there. Sorry to hear about the trouble you've encountered. Could you tell me the model of the phone you're using now? And please reinstall the latest version of the DJI Fly via our official website. If the problem persists, please feel free to contact us.
https://www.dji.com/downloads/djiapp/dji-fly

Thanks
I tried all that about 10 times
My tablet and phone is not on that list.
Hoping for another UPDATE FIX quickly

I updated by Samsung Galaxy Tab S6 tablet and the latest version of the DJI Fly App works without issue.  Are you sure you didn't get a bad download?

DowntownRDB Posted at 1-9 16:58
I updated by Samsung Galaxy Tab S6 tablet and the latest version of the DJI Fly App works without issue.  Are you sure you didn't get a bad download?

I  uninstalled it and reinstalled it many times
I tried my Samsung Galaxy 8 phone and it WORKS
Interesting it works on your  Tab S6
It list the devices it works with and there are no Android Tablets

Supported Mobile Devices

iOS V 1.5.4

Requires iOS 11.0 or above.

  Compatible with iPhone 13 Pro Max、iPhone 13 Pro、iPhone 13、iPhone 13 mini、iPhone 12 Pro Max、iPhone 12 Pro、iPhone 12、iPhone 12 mini、iPhone 11 Pro Max、iPhone 11 Pro、iPhone 11、iPhone XS Max、iPhone XS、iPhone XR、iPhone X、iPhone 8 Plus、iPhone 8、iPad Pro（9.7-inch）、iPad air2（9.7-inch）、iPad mini4（8-inch）、iPad Pro(10.5-inch)、iPad Pro 2018（11-inch）、iPad Pro （12.9-inch）
For older versions: Click to download

Android V 1.5.4

Requires Android 6.0 or above.

  Compatible with Samsung Galaxy S21，Samsung Galaxy S20，Samsung Galaxy S10+，Samsung Galaxy S10，Samsung Galaxy Note20，Samsung Galaxy Note10+ ，Samsung Galaxy Note9，HUAWEI Mate40 Pro，HUAWEI Mate30 Pro，HUAWEI P40 Pro，HUAWEI P30 Pro，HUAWEI P30，Honor 50 Pro，Mi 11，Mi 10，Mi MIX 4，Redmi Note 10，OPPO Find X3，OPPO Reno 4，vivo NEX 3，OnePlus 9 Pro，OnePlus 9，Pixel 6，Pixel 4，Pixel 3 XL
And Customer Service told me no Android tablets work yet.

BuzzCheeze Posted at 1-10 13:28
I  uninstalled it and reinstalled it many times
I tried my Samsung Galaxy 8 phone and it WORKS
Interesting it works on your  Tab S6

You are correct as no Android tablets are on the compatible list.  I know my Samsung Tab S6 works as I just finished flying my Mini 2 and my Mavic Air 2 and used the S6 as  my display.