There is bug in space.vmd decorator fragment:
—
#if ($blog.comments.size() > 0)
<a href="$req.contextPath$generalUtil.getPageUrl($blog)?showComments=true#comments">$blog.comments.size() comment#if($blog.comments.size() > 1)s#end</a>
#else
<a href="$req.contextPath$generalUtil.getPageUrl($blog)?showComments=true#comments">0 comments</a>
#end
—

If blog title contains national (non-ascii) character then $generalUtil.getPageUrl($blog) returns something like /pages/viewpage.action?pageId=xxx
As a result the final URL is
/pages/viewpage.action?pageId=xxx?showComments=true#comments
which gives server exception when clicked (as it contains two ? in URL, in this case second ? should be replaced with &)

The following workaround was made to avoid this issue:
—
#if ($generalUtil.getPageUrl($blog).indexOf("?") < 0)
#set( $sep = "?" )
#else
#set( $sep = "&" )
#end
#if ($blog.comments.size() > 0)
<a href="$req.contextPath$generalUtil.getPageUrl($blog)${sep}showComments=true#comments">$blog.comments.size() comment#if($blog.comments.size() > 1)s#end</a>
#else
<a href="$req.contextPath$generalUtil.getPageUrl($blog)${sep}showComments=true#comments">0 comments</a>
#end
—