reactjs user-agent bug, crash app css

I was hosting an app on my pc for a week so I am pretty sure there is no problem in code but some how next build this streans user agent thing added browser and breaks page

here is original component and how it seems in browser; component ...

render() {
        return (
            <div className="jumbotron search-form">
            <div className="row">
                <form className="form-horizontal" onSubmit={this.handleOnSubmit}>
                    <div className="col-md-10">
                        <input type="search" ref="location" onChange={this.handleOnChange} value={this.state.term} className="form-control" placeholder="get a five day forecast for your city" />
                    <div className="col-md-2">
                        <button type="submit" className="btn input-block-level btn-info form-control" title="Search for city" >
                            <i className='fa fa-search'></i> Search 


enter image description here

what is this and where it comes from?