Hmm, it's annoying when a phone manufacturer doesn't let the user wipe the cache.:-\
You sent me a PM and mentioned that this is one of the error messages you get:
java.lang.OutOfMemoryError: Failed to allocate a 44 byte allocation with 3976 free bytes and 3KB until OOM
at java.util.HashMap.resize(HashMap.java:511)
at java.util.HashMap.addEntry(HashMap.java:808)
at java.util.LinkedHashMap.addEntry(LinkedHashMap.jav a:464)
at java.util.HashMap.put(HashMap.java:436)
at org.json.JSONObject.put(JSONObject.java:264)
at com.android.mail.providers.Attachment.a(SourceFile :17)
at com.android.mail.providers.Attachment.a(SourceFile :5)
at com.android.mail.browse.MessageFooterView.b(Source File:15)
at com.android.mail.browse.MessageFooterView.onLoadFi nished(SourceFile:8)
at android.app.LoaderManagerImpl$LoaderInfo.callOnLoa dFinished(LoaderManager.java:489)
at android.app.LoaderManagerImpl$LoaderInfo.onLoadCom plete(LoaderManager.java:457)
at android.content.Loader.deliverResult(Loader.java:1 44)
at android.content.CursorLoader.deliverResult(CursorL oader.java:109)
at android.content.CursorLoader.deliverResult(CursorL oader.java:97)
at android.content.AsyncTaskLoader.dispatchOnLoadComp lete(AsyncTaskLoader.java:265)
at android.content.AsyncTaskLoader$LoadTask.onPostExe cute(AsyncTaskLoader.java:92)
at android.os.AsyncTask.finish(AsyncTask.java:667)
at android.os.AsyncTask.-wrap1(AsyncTask.java)
at android.os.AsyncTask$InternalHandler.handleMessage (AsyncTask.java:684)
at android.os.Handler.dispatchMessage(Handler.java:10 2)
at android.os.Looper.loop(Looper.java:163)
at android.app.ActivityThread.main(ActivityThread.jav a:6372)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCa ller.run(ZygoteInit.java:901)
at com.android.internal.os.ZygoteInit.main(ZygoteInit .java:791)
I'm not sure what to make of this. I'd suggest booting into Safe Mode as well, but from what I can find on the web, it also sounds like Xiaomi removed that very basic feature from the phone as well. You might just have to back up your important data, then do a factory reset. When setting the phone back up, make sure you don't automatically reinstall your previous apps. Then see if the problems persist. If they don't, then reinstall apps one by one to see if the problem comes back.