# iOS Crashed when try to set HLS Url before playing **URL:** \ **Category:** Wowza GoCoder SDK\ **Created:** [September 18, 2019, 3:45pm UTC](https://community.wowza.com/t/ios-crashed-when-try-to-set-hls-url-before-playing/53961 "2019-09-18T15:45:55Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Duc\_Bui1](https://avatars.discourse-cdn.com/v4/letter/d/a587f6/32.png) [@Duc\_Bui1](https://community.wowza.com/u/Duc_Bui1)\ **Post date:** [September 18, 2019, 3:45pm UTC](https://community.wowza.com/t/ios-crashed-when-try-to-set-hls-url-before-playing/53961/1 "2019-09-18T15:45:55Z")
I try to play a vod stream but failed then I set hls url and turn allow hls on but it always crash at method play with config. Please help me with this and why sdk announce that " **Could not connect to host. Check credentials."** ---
**Author:** ![Rose\_Power-Wowza\_Com](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/rose_power-wowza_com/32/431_2.png) [@Rose\_Power-Wowza\_Com](https://community.wowza.com/u/Rose_Power-Wowza_Com)\ **Post date:** [September 18, 2019, 4:57pm UTC](https://community.wowza.com/t/ios-crashed-when-try-to-set-hls-url-before-playing/53961/2 "2019-09-18T16:57:34Z")
Thanks for reaching out and asking @Duc Bui. The reason this is not working is because the Wowza GoCoder SDK does not support mp4s and is not for VOD. On our website, it says it is for live stream: **_The GoCoder SDK is free and lets you build live streaming apps for iOS and Android_** [https://www.wowza.com/products/gocoder](https://www.wowza.com/products/gocoder) You can stream mp4 files for HLS playback through Wowza Streaming Engine, but not with the GoCoder SDK. An interesting option for you may be to play an mp4 file as live stream and play it back through HLS: [https://www.wowza.com/docs/how-to-publish-a-video-file-as-a-live-stream](https://www.wowza.com/docs/how-to-publish-a-video-file-as-a-live-stream)