diff --git a/dist/converse.js b/dist/converse.js
index 47e57fc04..c0ee3a4a4 100644
--- a/dist/converse.js
+++ b/dist/converse.js
@@ -68845,7 +68845,9 @@ var __WEBPACK_AMD_DEFINE_FACTORY__, __WEBPACK_AMD_DEFINE_ARRAY__, __WEBPACK_AMD_
               if (args.length > 1) {
                 this.showErrorMessage(__(`Error: invalid number of arguments`));
               } else {
-                this.model.registerNickname();
+                this.model.registerNickname().then(err_msg => {
+                  if (err_msg) this.showErrorMessage(err_msg);
+                });
               }
 
               break;
@@ -70151,7 +70153,7 @@ function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }
         },
 
         async onConnectionStatusChanged() {
-          if (this.get('connection_status') === converse.ROOMSTATUS.ENTERED && _converse.auto_register_muc_nickname && this.get('reserved_nick')) {
+          if (this.get('connection_status') === converse.ROOMSTATUS.ENTERED && _converse.auto_register_muc_nickname && !this.get('reserved_nick')) {
             const result = await _converse.api.disco.supports(Strophe.NS.MUC_REGISTER, this.get('jid'));
 
             if (result.length) {
@@ -70870,7 +70872,7 @@ function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }
           // See https://xmpp.org/extensions/xep-0045.html#register
           const nick = this.get('nick'),
                 jid = this.get('jid');
-          let iq;
+          let iq, err_msg;
 
           try {
             iq = await _converse.api.sendIQ($iq({
@@ -70881,13 +70883,15 @@ function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }
               'xmlns': Strophe.NS.MUC_REGISTER
             }));
           } catch (e) {
-            if (sizzle('item-not-found[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-              _converse.log(`Can't register nickname ${nick} in the groupchat ${jid} which does not exist.`);
-            } else if (sizzle('not-allowed[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-              _converse.log(`You're not allowed to register in the groupchat ${jid}`);
+            if (sizzle('not-allowed[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
+              err_msg = __("You're not allowed to register yourself in this groupchat.");
+            } else if (sizzle('registration-required[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
+              err_msg = __("You're not allowed to register in this groupchat because it's members-only.");
             }
 
-            return _converse.log(e, Strophe.LogLevel.ERROR);
+            _converse.log(e, Strophe.LogLevel.ERROR);
+
+            return err_msg;
           }
 
           const required_fields = _.map(sizzle('field required', iq), 'parentElement');
@@ -70912,15 +70916,17 @@ function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }
               'var': 'muc#register_roomnick'
             }).c('value').t(nick));
           } catch (e) {
-            if (sizzle('conflict[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-              _converse.log(`Can't register nickname ${nick} in the groupchat ${jid}, it's already taken.`);
-            } else if (sizzle('service-unavailable[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-              _converse.log(`Can't register nickname ${nick} in the groupchat ${jid}, it doesn't support registration.`);
+            if (sizzle('service-unavailable[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
+              err_msg = __("Can't register your nickname in this groupchat, it doesn't support registration.");
             } else if (sizzle('bad-request[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-              _converse.log(`Can't register nickname ${nick} in the groupchat ${jid}, invalid data form supplied.`);
+              err_msg = __("Can't register your nickname in this groupchat, invalid data form supplied.");
             }
 
-            return _converse.log(e, Strophe.LogLevel.ERROR);
+            _converse.log(err_msg);
+
+            _converse.log(e, Strophe.LogLevel.ERROR);
+
+            return err_msg;
           }
         },
 
diff --git a/src/converse-muc-views.js b/src/converse-muc-views.js
index 4137954a5..9467d8531 100644
--- a/src/converse-muc-views.js
+++ b/src/converse-muc-views.js
@@ -1003,7 +1003,9 @@
                             if (args.length > 1) {
                                 this.showErrorMessage(__(`Error: invalid number of arguments`))
                             } else {
-                                this.model.registerNickname();
+                                this.model.registerNickname().then(err_msg => {
+                                    if (err_msg) this.showErrorMessage(err_msg)
+                                });
                             }
                             break;
                         case 'revoke':
diff --git a/src/converse-muc.js b/src/converse-muc.js
index 420cac818..6acbc4cf9 100644
--- a/src/converse-muc.js
+++ b/src/converse-muc.js
@@ -198,7 +198,7 @@
                 async onConnectionStatusChanged () {
                     if (this.get('connection_status') === converse.ROOMSTATUS.ENTERED &&
                             _converse.auto_register_muc_nickname &&
-                            this.get('reserved_nick')) {
+                            !this.get('reserved_nick')) {
 
                         const result = await _converse.api.disco.supports(Strophe.NS.MUC_REGISTER, this.get('jid'));
                         if (result.length) {
@@ -818,7 +818,7 @@
                     // See https://xmpp.org/extensions/xep-0045.html#register
                     const nick = this.get('nick'),
                           jid = this.get('jid');
-                    let iq;
+                    let iq, err_msg;
                     try {
                         iq = await _converse.api.sendIQ(
                             $iq({
@@ -828,12 +828,13 @@
                             }).c('query', {'xmlns': Strophe.NS.MUC_REGISTER})
                         );
                     } catch (e) {
-                        if (sizzle('item-not-found[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-                            _converse.log(`Can't register nickname ${nick} in the groupchat ${jid} which does not exist.`);
-                        } else if (sizzle('not-allowed[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-                            _converse.log(`You're not allowed to register in the groupchat ${jid}`);
+                        if (sizzle('not-allowed[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
+                            err_msg = __("You're not allowed to register yourself in this groupchat.");
+                        } else if (sizzle('registration-required[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
+                            err_msg = __("You're not allowed to register in this groupchat because it's members-only.");
                         }
-                        return _converse.log(e, Strophe.LogLevel.ERROR);
+                        _converse.log(e, Strophe.LogLevel.ERROR);
+                        return err_msg;
                     }
                     const required_fields = _.map(sizzle('field required', iq), 'parentElement');
                     if (required_fields.length > 1 || required_fields[0].getAttribute('var') !== 'muc#register_roomnick') {
@@ -850,14 +851,14 @@
                                     .c('field', {'var': 'muc#register_roomnick'}).c('value').t(nick)
                         );
                     } catch (e) {
-                        if (sizzle('conflict[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-                            _converse.log(`Can't register nickname ${nick} in the groupchat ${jid}, it's already taken.`);
-                        } else if (sizzle('service-unavailable[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-                            _converse.log(`Can't register nickname ${nick} in the groupchat ${jid}, it doesn't support registration.`);
+                        if (sizzle('service-unavailable[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
+                            err_msg = __("Can't register your nickname in this groupchat, it doesn't support registration.");
                         } else if (sizzle('bad-request[xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"]', e).length) {
-                            _converse.log(`Can't register nickname ${nick} in the groupchat ${jid}, invalid data form supplied.`);
+                            err_msg = __("Can't register your nickname in this groupchat, invalid data form supplied.");
                         }
-                        return _converse.log(e, Strophe.LogLevel.ERROR);
+                        _converse.log(err_msg);
+                        _converse.log(e, Strophe.LogLevel.ERROR);
+                        return err_msg;
                     }
                 },