Empty screen when starting just released Traccar Manager 2.9 on iOS

[AlphaDE]

Describe the bug Just released Traccar Manager shows an empty screen when the app is started.

To Reproduce Steps to reproduce the behavior:

1. Install version 2.9 from App Store
2. Start app
3. App starts, screen is empty
4. See error

Expected behavior The app should show it's usual UI

Smartphone (please complete the following information):

• Device: iPhone 12
• OS: iOS 15.2

[tananaev]

Do you have a screenshot?

[AlphaDE]

Here we go.

[tananaev]

Just to clarify, are you expecting server selection screen or you already selected the server?

[AlphaDE]

The app was updated, a server was already selected and configured. The configured server is up and running.

[AlphaDE]

https://user-images.githubusercontent.com/24697458/147404324-88f8420f-f4aa-429b-ad6e-e80683017e41.mp4

See the attached video also for V 2.10

[tananaev]

The video is too short. Are you sure you waited enough time?

[AlphaDE]

Here another one with 1.5 min duration... no change

https://user-images.githubusercontent.com/24697458/147414846-6129cb28-f299-411d-9a48-690645d4f8fe.mp4

.

[tananaev]

Are you using your own server? Have you tried one of the demo servers?

[AlphaDE]

I am using an own server, on my Android phone with Manager 2.18, it does work, same when accessing the website via Chrome on the PC.

[AlphaDE]

On the iPhone the demo server does work, does the iPhone app possible has a problem with the Let's Encrypt certificate (access only via https to my server)?

[tananaev]

It shouldn't have problems with a valid certificate.

[AlphaDE]

Ok.

[AlphaDE]

Found the problem.. first my fault, misconfiguration on my Apache web proxy redirecting only IPv4 but not IPv6, so IPv6 led to the wrong website. The iPhone used IPv6, my PC and my Android phone used IPv4. Nevertheless recommend to show an error if there is no valid server instead of the blank screen.