The template "register_adminadd_eml.tpl" was missing for all languages except german. That lead to an empty page when adding users.

mod/network.php

@@ -738,7 +738,7 @@ die("ss");
 			// This problem can occur expecially with imported facebook posts
 			$max_comments = get_config("system", "max_comments");
 			if ($max_comments == 0)
-				$max_comments = 1000;
+				$max_comments = 100;
 
 			$items = array();
 

view/en/smarty3/register_adminadd_eml.tpl

@@ -0,0 +1,32 @@
+Dear {{$username}},
+	the administrator of {{$sitename}} has set up an account for you.
+
+The login details are as follows:
+
+
+Site Location:	{{$siteurl}}
+Login Name:	{{$email}}
+Password:	{{$password}}
+
+You may change your password from your account "Settings" page after logging 
+in.
+
+Please take a few moments to review the other account settings on that page.
+
+You may also wish to add some basic information to your default profile 
+(on the "Profiles" page) so that other people can easily find you.
+
+We recommend setting your full name, adding a profile photo,
+adding some profile "keywords" (very useful in making new friends) - and 
+perhaps what country you live in; if you do not wish to be more specific
+than that.
+
+We fully respect your right to privacy, and none of these items are necessary. 
+If you are new and do not know anybody here, they may help
+you to make some new and interesting friends.  
+
+
+Thank you and welcome to {{$sitename}}.
+
+Sincerely,
+	{{$sitename}} Administrator