android - Fatal Exception: String can't be cast to Spannable -

my app works exception of few devices. on 1 such device, fatal exception in 1 of activities. error java.lang.classcastexception: java.lang.string cannot cast android.text.spannable ... ... at android.widget.textview.setenabled(textview.java:1432)

stack trace

05-02 09:18:19.917: e/androidruntime(20587): fatal exception: main 05-02 09:18:19.917: e/androidruntime(20587): java.lang.classcastexception: java.lang.string cannot cast android.text.spannable 05-02 09:18:19.917: e/androidruntime(20587):    @ android.widget.textview.setenabled(textview.java:1432) 05-02 09:18:19.917: e/androidruntime(20587):    @ com.myapp.android.menu.loginfragment.checkifanyfieldisempty(loginfragment.java:512) 05-02 09:18:19.917: e/androidruntime(20587):    @ com.myapp.android.menu.loginfragment.oncreateview(loginfragment.java:183) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.support.v4.app.fragment.performcreateview(fragment.java:1460) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.support.v4.app.fragmentmanagerimpl.movetostate(fragmentmanager.java:911) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.support.v4.app.fragmentmanagerimpl.movetostate(fragmentmanager.java:1088) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.support.v4.app.backstackrecord.run(backstackrecord.java:682) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.support.v4.app.fragmentmanagerimpl.execpendingactions(fragmentmanager.java:1444) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.support.v4.app.fragmentmanagerimpl$1.run(fragmentmanager.java:429) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.os.handler.handlecallback(handler.java:615) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.os.handler.dispatchmessage(handler.java:92) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.os.looper.loop(looper.java:137) 05-02 09:18:19.917: e/androidruntime(20587):    @ android.app.activitythread.main(activitythread.java:4962) 05-02 09:18:19.917: e/androidruntime(20587):    @ java.lang.reflect.method.invokenative(native method) 05-02 09:18:19.917: e/androidruntime(20587):    @ java.lang.reflect.method.invoke(method.java:511) 05-02 09:18:19.917: e/androidruntime(20587):    @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:1004) 05-02 09:18:19.917: e/androidruntime(20587):    @ com.android.internal.os.zygoteinit.main(zygoteinit.java:771) 05-02 09:18:19.917: e/androidruntime(20587):    @ dalvik.system.nativestart.main(native method) 

here snippets of code surrounding error.

xml layout code

<com.myapp.android.view.styledbutton         android:id="@+id/login_sign_in"         style="@style/button_blue"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:background="@drawable/state_list_login"         android:textcolor="@color/white"         android:imeoptions="actiondone"         android:padding="10dp"         android:text="@string/sign_in" /> 

custom button java code

public class styledbutton extends button { //variables private final string bold = "fonts/arial.ttf"; private final string normal = "fonts/arial_bold.ttf";  private string mcustomfont = null;  /**  * constructor  * @param context  */ public styledbutton(context context) {     super(context); }  /**  * constructor  * @param context  * @param attrs  */ public styledbutton(context context, attributeset attrs) {     super(context, attrs);     setcustomattributes(attrs); }  /**  * set custom attributes  * @param attrs  */ private void setcustomattributes(attributeset attrs) {     typedarray a=getcontext().obtainstyledattributes(attrs,r.styleable.styledtextview);     mcustomfont = a.getstring(r.styleable.styledtextview_fontasset);     if(mcustomfont != null) {         if(!isineditmode()) {             customfontmanager fontmanager = customfontmanager.getinstance();             super.settypeface(fontmanager.getfont(getcontext().getassets(), mcustomfont));         }     }     a.recycle(); }  /**  * set type face  */ public void settypeface(typeface tf, int style) {     customfontmanager fontmanager = customfontmanager.getinstance();     if(isineditmode()) {         super.settypeface(tf,style);         return;     }     if(mcustomfont!=null) {         super.settypeface(fontmanager.getfont(getcontext().getassets(), mcustomfont));         return;     }     switch (style) {         case typeface.normal:             super.settypeface(fontmanager.getfont(getcontext().getassets(), normal));             break;         case typeface.bold:             super.settypeface(fontmanager.getfont(getcontext().getassets(), bold));             break;         default:             super.settypeface(fontmanager.getfont(getcontext().getassets(), normal));             break;     } } 

}

java code causing error

    private styledbutton msignin;      public void checkifanyfieldisempty() {     if (memailempty || mpasswordempty) {         msignin.setenabled(false);     } else {         msignin.setenabled(true);     }  } 

the line of code msignin.setenabled(false) causing error. if comment out or replace both if , else read msignin.setenabled(true) app runs fine.

again. code works fine on majority of devices.

did make style button spannable? example, textview should

textview.settext("hai", textview.buffertype.spannable);