Cannot pick file in iOS

I built an iOS ownCloud app v3.5.3 from source. The main client is worked fine but when I use another app to upload a file and choose my ownCloud app for picking file. Once the share sheet is opened it will disappear soon. The official ownCloud has no such problem but happen in my self built app.
Is there any setting of source, xcode or plist or device should I notice?