# SBUChannelViewController cannot be opened in V1.2.5 **URL:** \ **Category:** iOS\ **Tags:** ios, bug\ **Created:** [October 21, 2020, 7:50am UTC](https://community.sendbird.com/t/sbuchannelviewcontroller-cannot-be-opened-in-v1-2-5/1167 "2020-10-21T07:50:15Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Minon\_Weerasinghe](https://sea2.discourse-cdn.com/flex020/user_avatar/community.sendbird.com/minon_weerasinghe/32/132_2.png) [@Minon\_Weerasinghe](https://community.sendbird.com/u/Minon_Weerasinghe)\ **Post date:** [October 21, 2020, 7:50am UTC](https://community.sendbird.com/t/sbuchannelviewcontroller-cannot-be-opened-in-v1-2-5/1167/1 "2020-10-21T07:50:15Z")
When I try to open the SBUChannelViewController via the SBUChannelListViewController I get the following crash. `Mutating a priority from required to not on an installed constraint (or vice-versa) is not supported. You passed priority 250 and the existing priority was 1000.` This works fine in V 1.1.3 but after I update my pods it no longer works. ---
**Author:** ![Woo](https://sea2.discourse-cdn.com/flex020/user_avatar/community.sendbird.com/woo/32/125_2.png) [@Woo](https://community.sendbird.com/u/Woo)\ **Post date:** [October 21, 2020, 8:08am UTC](https://community.sendbird.com/t/sbuchannelviewcontroller-cannot-be-opened-in-v1-2-5/1167/2 "2020-10-21T08:08:11Z")
@Minon_Weerasinghe Would you tell us what Xcode version you are using? I don’t see any problems on sample to open up `SBUChannelViewController` ---
**Author:** ![Minon\_Weerasinghe](https://sea2.discourse-cdn.com/flex020/user_avatar/community.sendbird.com/minon_weerasinghe/32/132_2.png) [@Minon\_Weerasinghe](https://community.sendbird.com/u/Minon_Weerasinghe)\ **Post date:** [October 21, 2020, 8:49am UTC](https://community.sendbird.com/t/sbuchannelviewcontroller-cannot-be-opened-in-v1-2-5/1167/3 "2020-10-21T08:49:37Z")
Xcode Version 12.0.1 (12A7300) Could this be because I’m not directly using the SBUChannelListVC and SBUChannelVC. I inherit from these two classes because I want to inject certain properties to the VCs. ---
**Author:** ![Tez](https://sea2.discourse-cdn.com/flex020/user_avatar/community.sendbird.com/tez/32/146_2.png) [@Tez](https://community.sendbird.com/u/Tez)\ **Post date:** [October 29, 2020, 1:44am UTC](https://community.sendbird.com/t/sbuchannelviewcontroller-cannot-be-opened-in-v1-2-5/1167/4 "2020-10-29T01:44:36Z")
Hello @Minon_Weerasinghe, What are the additional implementations of the class? And, when a crash occurs, it may be helpful to inform the crash stack. ---
**Author:** ![Ashish\_Yadav](https://sea2.discourse-cdn.com/flex020/user_avatar/community.sendbird.com/ashish_yadav/32/669_2.png) [@Ashish\_Yadav](https://community.sendbird.com/u/Ashish_Yadav)\ **Post date:** [November 11, 2020, 2:47pm UTC](https://community.sendbird.com/t/sbuchannelviewcontroller-cannot-be-opened-in-v1-2-5/1167/5 "2020-11-11T14:47:03Z")
I am also facing the same issue. It works fine in the iOS 14 simulator. But when I run the same app on a physical device (with ios 12), the above error occurred. Channel list loaded successfully when you click on a particular channel, then the app is crashing with this error. This works fine in the iOS version above 12, but in the ios version below or equal to 12 is crashing. Please update the framework. Thanks ---
**Author:** ![Woo](https://sea2.discourse-cdn.com/flex020/user_avatar/community.sendbird.com/woo/32/125_2.png) [@Woo](https://community.sendbird.com/u/Woo)\ **Post date:** [November 30, 2020, 4:40am UTC](https://community.sendbird.com/t/sbuchannelviewcontroller-cannot-be-opened-in-v1-2-5/1167/6 "2020-11-30T04:40:11Z")
@Ashish_Yadav Thanks for your insight! so apparently something is not working properly under iOS 12. Have you ever try to run simulator with iOS 12?