diff --git a/scripts/ZoneMinder/lib/ZoneMinder/Filter.pm b/scripts/ZoneMinder/lib/ZoneMinder/Filter.pm
index 852a05e9b..b48946d1f 100644
--- a/scripts/ZoneMinder/lib/ZoneMinder/Filter.pm
+++ b/scripts/ZoneMinder/lib/ZoneMinder/Filter.pm
@@ -203,11 +203,10 @@ sub Sql {
             $self->{Sql} .= "weekday( E.EndTime )";
 
 # 
-          } elsif ( $term->{attr} eq 'EventExists' ) {
-            push @{$self->{PreConditions}}, $term;
+          } elsif ( $term->{attr} eq 'ExistsInFileSystem' ) {
+            push @{$self->{PostSQLConditions}}, $term;
           } elsif ( $term->{attr} eq 'DiskSpace' ) {
             $self->{Sql} .= 'E.DiskSpace';
-            push @{$self->{PostConditions}}, $term;
           } elsif ( $term->{attr} eq 'DiskPercent' ) {
             $self->{Sql} .= 'zmDiskPercent';
             $self->{HasDiskPercent} = !undef;
diff --git a/web/includes/Event.php b/web/includes/Event.php
index a9eb99d59..a2f4f47c9 100644
--- a/web/includes/Event.php
+++ b/web/includes/Event.php
@@ -50,6 +50,9 @@ class Event extends ZM_Object {
   public static function clear_cache() {
     return ZM_Object::_clear_cache(get_class());
   }
+  public function remove_from_cache() {
+    return ZM_Object::_remove_from_cache(get_class(), $this);
+  }
 
   public function Storage( $new = null ) {
     if ( $new ) {
diff --git a/web/includes/Filter.php b/web/includes/Filter.php
index 5a441b2ac..d9ca02f0c 100644
--- a/web/includes/Filter.php
+++ b/web/includes/Filter.php
@@ -40,8 +40,11 @@ class Filter extends ZM_Object {
   public function sql() {
     if ( ! isset($this->_sql) ) {
       foreach ( $this->FilterTerms() as $term ) {
-        if ( ! ($term->is_pre_sql() or $term->is_post_sql()) )
+        if ( ! ($term->is_pre_sql() or $term->is_post_sql()) ) {
           $this->_sql .= $term->sql();
+        } else {
+          $this->_sql .= '1';
+        }
       } # end foreach term
     }
     return $this->_sql;
diff --git a/web/includes/FilterTerm.php b/web/includes/FilterTerm.php
index 63eac2890..1cb720a24 100644
--- a/web/includes/FilterTerm.php
+++ b/web/includes/FilterTerm.php
@@ -164,13 +164,13 @@ class FilterTerm {
     case 'IS' :
       # Odd will be replaced with 1
       # Even will be replaced with 0
-      if ( $this->value == 'Odd' or $this->value == 'Even' )  {
+      if ( $this->val == 'Odd' or $this->val == 'Even' )  {
         return ' % 2 = ';
       } else {
         return ' IS ';
       }
     case 'IS NOT' :
-      if ( $this->value == 'Odd' or $this->value == 'Even' )  {
+      if ( $this->val == 'Odd' or $this->val == 'Even' )  {
         return ' % 2 = ';
       }
       return ' IS NOT ';
@@ -182,7 +182,7 @@ class FilterTerm {
   /* Some terms don't have related SQL */
   public function sql() {
     if ( $this->attr == 'ExistsInFileSystem' ) {
-      return '';
+      return '1';
     }
 
     $sql = '';
diff --git a/web/includes/Object.php b/web/includes/Object.php
index f49497276..d7fa8c654 100644
--- a/web/includes/Object.php
+++ b/web/includes/Object.php
@@ -141,6 +141,11 @@ class ZM_Object {
     global $object_cache;
     $object_cache[$class] = array();
   }
+  public function _remove_from_cache($class, $object) {
+    global $object_cache;
+    unset($object_cache[$class][$object->Id()]);
+    Logger::Debug("Unsset $class " . $object->Id() . " " . count($object_cache[$class]));
+  }
 
   public static function Objects_Indexed_By_Id($class) {
     $results = array();
diff --git a/web/includes/actions/filter.php b/web/includes/actions/filter.php
index a2e272025..2725c70fc 100644
--- a/web/includes/actions/filter.php
+++ b/web/includes/actions/filter.php
@@ -95,6 +95,7 @@ if ( isset($_REQUEST['object']) and ( $_REQUEST['object'] == 'filter' ) ) {
       } else if ( $filter->Background() ) {
         $filter->control('start');
       }
+      $redirect = '?view=filter&Id='.$filter->Id();
 
     } else if ( $action == 'control' ) {
       if ( $_REQUEST['command'] == 'start'
diff --git a/web/skins/classic/views/console.php b/web/skins/classic/views/console.php
index 0a8ce2905..20be7eeeb 100644
--- a/web/skins/classic/views/console.php
+++ b/web/skins/classic/views/console.php
@@ -286,10 +286,10 @@ for( $monitor_i = 0; $monitor_i < count($displayMonitors); $monitor_i += 1 ) {
   $imgHTML='';
   if ( ZM_WEB_LIST_THUMBS && ($monitor['Status'] == 'Connected') && $running ) {
     $options = array();
-    $ratio_factor = $Monitor->Height() / $Monitor->Width();
+    $ratio_factor = $Monitor->ViewHeight() / $Monitor->ViewWidth();
     $options['width'] = ZM_WEB_LIST_THUMB_WIDTH;
     $options['height'] = ZM_WEB_LIST_THUMB_HEIGHT ? ZM_WEB_LIST_THUMB_HEIGHT : ZM_WEB_LIST_THUMB_WIDTH*$ratio_factor;
-    $options['scale'] = intval(100*ZM_WEB_LIST_THUMB_WIDTH / $Monitor->Width());
+    $options['scale'] = intval(100*ZM_WEB_LIST_THUMB_WIDTH / $Monitor->ViewWidth());
     $options['mode'] = 'single';
 
     $stillSrc = $Monitor->getStreamSrc($options);
diff --git a/web/skins/classic/views/events.php b/web/skins/classic/views/events.php
index 6e85ad3ee..08e0a51a1 100644
--- a/web/skins/classic/views/events.php
+++ b/web/skins/classic/views/events.php
@@ -58,7 +58,7 @@ if ( $_POST ) {
 
 $failed = !$filter->test_pre_sql_conditions();
 if ( $failed ) {
-  ZM\Logger::Debug("Pre conditions failed, not doing sql");
+  ZM\Logger::Debug('Pre conditions failed, not doing sql');
 }
 
 $results = $failed ? null : dbQuery($eventsSql);
@@ -189,14 +189,22 @@ xhtmlHeaders(__FILE__, translate('Events'));
 $count = 0;
 $disk_space_total = 0;
 if ( $results ) {
+  $events = array();
 
   while ( $event_row = dbFetchNext($results) ) {
     $event = new ZM\Event($event_row);
 
     if ( !$filter->test_post_sql_conditions($event) ) {
-      ZM\Logger::Debug("Failed post conditions");
+      $event->remove_from_cache();
       continue;
     }
+    $events[] = $event;
+    if ( $limit and (count($events) > $limit) ) {
+      break;
+    }
+    ZM\Logger::Debug("Have " . count($events) . " events, limit $limit");
+  }
+  foreach ( $events as $event ) {
 
     $scale = max(reScale(SCALE_BASE, $event->DefaultScale(), ZM_WEB_DEFAULT_SCALE), SCALE_BASE);
 ?>
@@ -280,7 +288,7 @@ if ( $results ) {
 ?>
             </tr>
 <?php
-}
+} # end foreach row
 ?>
           </tbody>
 <?php
diff --git a/web/skins/classic/views/frames.php b/web/skins/classic/views/frames.php
index ba1a3a229..3a6791f91 100644
--- a/web/skins/classic/views/frames.php
+++ b/web/skins/classic/views/frames.php
@@ -142,6 +142,7 @@ xhtmlHeaders(__FILE__, translate('Frames').' - '.$Event->Id());
         data-detail-view="true"
         data-detail-formatter="detailFormatter"
         data-show-toggle="true"
+        data-show-jump-to="true"
         class="table-sm table-borderless">
 
         <thead>
diff --git a/web/skins/classic/views/js/console.js b/web/skins/classic/views/js/console.js
index 10b78dce2..4b804a437 100644
--- a/web/skins/classic/views/js/console.js
+++ b/web/skins/classic/views/js/console.js
@@ -53,7 +53,7 @@ function setButtonStates( element ) {
 }
 
 function addMonitor(element) {
-  createPopup( '?view=monitor', 'zmMonitor0', 'monitor' );
+  window.location.assign('?view=monitor');
 }
 
 function cloneMonitor(element) {
@@ -73,7 +73,7 @@ function cloneMonitor(element) {
     }
   } // end foreach element
   if ( monitorId != -1 ) {
-    createPopup( '?view=monitor&dupId='+monitorId, 'zmMonitor0', 'monitor' );
+    window.location.assign('?view=monitor&dupId='+monitorId);
   }
 }
 
@@ -97,11 +97,11 @@ function editMonitor( element ) {
     }
   } // end foreach checkboxes
   if ( monitorIds.length == 1 ) {
-    createPopup( '?view=monitor&mid='+monitorIds[0], 'zmMonitor'+monitorIds[0], 'monitor' );
+    window.location.assign('?view=monitor&mid='+monitorIds[0]);
   } else if ( monitorIds.length > 1 ) {
-    createPopup( '?view=monitors&'+(monitorIds.map(function(mid) {
+    window.location.assign( '?view=monitors&'+(monitorIds.map(function(mid) {
       return 'mids[]='+mid;
-    }).join('&')), 'zmMonitors', 'monitors' );
+    }).join('&')));
   }
 }
 
@@ -147,7 +147,7 @@ function initPage() {
 
   reloadWindow.periodical(consoleRefreshTimeout);
   if ( showVersionPopup ) {
-    createPopup('?view=version', 'zmVersion', 'version');
+    window.location.assign('?view=version');
   }
   if ( showDonatePopup ) {
     $j('#donate').modal('show');
diff --git a/web/skins/classic/views/js/monitor.js b/web/skins/classic/views/js/monitor.js
index 3f962ebfb..23e9ec577 100644
--- a/web/skins/classic/views/js/monitor.js
+++ b/web/skins/classic/views/js/monitor.js
@@ -68,6 +68,8 @@ function loadLocations( element ) {
 }
 
 function initPage() {
+  var backBtn = $j('#backBtn');
+
   //var protocolSelector = $('contentForm').elements['newMonitor[Protocol]'];
   //if ( $(protocolSelector).getTag() == 'select' )
   //updateMethods( $(protocolSelector) );
@@ -135,8 +137,22 @@ function initPage() {
     el.onchange = window['change_WebColour'].bind(el);
   });
 
-
   $j('.chosen').chosen();
+
+  // Don't enable the back button if there is no previous zm page to go back to
+  backBtn.prop('disabled', !document.referrer.length);
+
+  // Manage the BACK button
+  document.getElementById("backBtn").addEventListener("click", function onBackClick(evt) {
+    evt.preventDefault();
+    window.history.back();
+  });
+
+  // Manage the REFRESH Button
+  document.getElementById("refreshBtn").addEventListener("click", function onRefreshClick(evt) {
+    evt.preventDefault();
+    window.location.reload(true);
+  });
 } // end function initPage()
 
 function change_WebColour() {
diff --git a/web/skins/classic/views/logout.php b/web/skins/classic/views/logout.php
index e51182064..86e07605a 100644
--- a/web/skins/classic/views/logout.php
+++ b/web/skins/classic/views/logout.php
@@ -32,7 +32,7 @@ global $CLANG;
         <p><?php echo sprintf( $CLANG['CurrentLogin'], $user['Username'] ) ?></p>
       </div>
       <div class="modal-footer">
-        <form name="contentForm" id="contentForm" method="post" action="?">
+        <form name="logoutForm" id="logoutForm" method="post" action="?">
           <input type="hidden" name="view" value="logout"/>
           <button type="submit" name="action" value="logout"><?php echo translate('Logout') ?></button>
           <?php if ( ZM_USER_SELF_EDIT ) echo '<button type="submit" name="action" value="config">'.translate('Config').'</button>'.PHP_EOL; ?>
diff --git a/web/skins/classic/views/monitor.php b/web/skins/classic/views/monitor.php
index aa54fa926..d96736252 100644
--- a/web/skins/classic/views/monitor.php
+++ b/web/skins/classic/views/monitor.php
@@ -381,9 +381,17 @@ $codecs = array(
 
 xhtmlHeaders(__FILE__, translate('Monitor').' - '.validHtmlStr($monitor->Name()));
 getBodyTopHTML();
+echo getNavBarHTML();
 ?>
   <div id="page">
-    <div id="header">
+    <div class="d-flex flex-row justify-content-between px-3 py-1">
+    
+      <div class="" id="toolbar" >
+        <button id="backBtn" class="btn btn-normal" data-toggle="tooltip" data-placement="top" title="<?php echo translate('Back') ?>" disabled><i class="fa fa-arrow-left"></i></button>
+        <button id="refreshBtn" class="btn btn-normal" data-toggle="tooltip" data-placement="top" title="<?php echo translate('Refresh') ?>" ><i class="fa fa-refresh"></i></button>
+      </div>
+      
+    <h2><?php echo translate('Monitor') ?> - <?php echo validHtmlStr($monitor->Name()) ?><?php if ( $monitor->Id() ) { ?> (<?php echo $monitor->Id()?>)<?php } ?></h2>
 <?php
 if ( canEdit('Monitors') ) {
   if ( isset($_REQUEST['dupId']) ) {
@@ -394,19 +402,19 @@ if ( canEdit('Monitors') ) {
 <?php
   }
 ?>
-    <div id="headerButtons">
-      <?php echo makePopupLink('?view=monitorprobe&mid='.$monitor->Id(), 'zmMonitorProbe'.$monitor->Id(), 'monitorprobe', translate('Probe')); ?>
+    <div id="">
+      <?php echo makeLink('?view=monitorprobe&mid='.$monitor->Id(), translate('Probe')); ?>
 <?php
   if ( ZM_HAS_ONVIF ) {
-       echo makePopupLink('?view=onvifprobe&mid='.$monitor->Id(), 'zmOnvifProbe'.$monitor->Id(), 'onvifprobe', translate('OnvifProbe'));
+       echo makeLink('?view=onvifprobe&mid='.$monitor->Id(), translate('OnvifProbe'));
   }
 ?>
-      <?php echo makePopupLink('?view=monitorpreset&mid=' . $monitor->Id(), 'zmMonitorPreset' . $monitor->Id(), 'monitorpreset', translate('Presets')); ?>
+      <?php echo makeLink('?view=monitorpreset&mid=' . $monitor->Id(), translate('Presets')); ?>
     </div>
 <?php
 } // end if canEdit('Monitors')
 ?>
-    <h2><?php echo translate('Monitor') ?> - <?php echo validHtmlStr($monitor->Name()) ?><?php if ( $monitor->Id() ) { ?> (<?php echo $monitor->Id()?>)<?php } ?></h2>
+    
   </div>
   <div id="content">
     <ul class="tabList">