I could not access on your site with username/password you have provided. I’m not sure if your site is using LESS or CSS file
If your site is using CSS file you can change here:
<blockquote>templates/ja_mero/css/template-responsive.css</blockquote>
from
.ja-mainnav {
background: #e6e6e6
border-top: 1px solid #d9d9d9
height: auto;
margin-left: -20px;
margin-right: -20px;
}
change to
.ja-mainnav {
background: #e6e6e6
border-top: 1px solid #d9d9d9
height: auto;
margin-left: -20px;
margin-right: -20px;
display: none;
}
If LESS:
from
.ja-mainnav {
height: @navbarHeight;
position: relative;
z-index: 40;
}
change to
.ja-mainnav {
height: @navbarHeight;
position: relative;
z-index: 40;
display: none;
}
If you still see error after the above fixes, you can pm me with admin access and ftp account. I shall help you out of it