diff --git a/UnitTestContrib/test/unit/SeleniumConfigTests.pm b/UnitTestContrib/test/unit/SeleniumConfigTests.pm
@@ -1,22 +1,24 @@
 use strict;
 
 package SeleniumConfigTests;
-
-use FoswikiSeleniumTestCase;
-our @ISA = qw( FoswikiSeleniumTestCase );
+use v5.14;
 
 use Foswiki::Func;
 
-sub new {
-    my $self = shift()->SUPER::new( 'SeleniumConfig', @_ );
-    return $self;
-}
+use Moo;
+use namespace::clean;
+extends qw( FoswikiSeleniumTestCase );
+
+around BUILDARGS => sub {
+    my $orig = shift;
+    return $orig->( @_, testSuite => 'SeleniumConfig' );
+};
 
 sub verify_SeleniumRc_config {
     my $this = shift;
     $this->selenium->open_ok(
         Foswiki::Func::getScriptUrl(
-            $this->{test_web}, $this->{test_topic}, 'view'
+            $this->test_web, $this->test_topic, 'view'
         )
     );
     $this->login();
@@ -38,7 +40,7 @@ sub verify_SeleniumRc_like_failure_reporting {
     my $this = shift;
     $this->selenium->open_ok(
         Foswiki::Func::getScriptUrl(
-            $this->{test_web}, $this->{test_topic}, 'view'
+            $this->test_web, $this->test_topic, 'view'
         )
     );
     eval {

diff --git a/UnitTestContrib/test/unit/SemiAutomaticTestCaseTests.pm b/UnitTestContrib/test/unit/SemiAutomaticTestCaseTests.pm
@@ -1,13 +1,13 @@
 package SemiAutomaticTestCaseTests;
-use strict;
-use warnings;
-
-use FoswikiFnTestCase();
-our @ISA = qw( FoswikiFnTestCase );
+use v5.14;
 
 use Foswiki();
 use Foswiki::UI::View();
-use Error qw( :try );
+use Try::Tiny;
+
+use Moo;
+use namespace::clean;
+extends qw( FoswikiFnTestCase );
 
 my $VIEW_UI_FN;
 
@@ -128,9 +128,10 @@ text
 @
 T3
 
-sub set_up {
+around set_up => sub {
+    my $orig = shift;
     my $this = shift;
-    $this->SUPER::set_up();
+    $orig->( $this, @_ );
 
     # Testcases are written using good anchors
     $Foswiki::cfg{RequireCompatibleAnchors} = 0;
@@ -149,17 +150,24 @@ sub set_up {
 
     # This user is used in some testcases. All we need to do is make sure
     # their topic exists in the test users web
-    if ( !$this->{session}
-        ->topicExists( $Foswiki::cfg{UsersWebName}, 'WikiGuest' ) )
+    if (
+        !$this->session->topicExists(
+            $Foswiki::cfg{UsersWebName}, 'WikiGuest'
+        )
+      )
     {
         my ($to) =
           Foswiki::Func::readTopic( $Foswiki::cfg{UsersWebName}, 'WikiGuest' );
         $to->text('This user is used in some testcases');
         $to->save();
         $to->finish();
     }
-    if ( !$this->{session}
-        ->topicExists( $Foswiki::cfg{UsersWebName}, 'UnknownUser' ) )
+    if (
+        !$this->session->topicExists(
+            $Foswiki::cfg{UsersWebName},
+            'UnknownUser'
+        )
+      )
     {
         my ($to) =
           Foswiki::Func::readTopic( $Foswiki::cfg{UsersWebName},
@@ -168,25 +176,25 @@ sub set_up {
         $to->save();
         $to->finish();
     }
+};
 
-    return;
-}
-
-sub tear_down {
+around tear_down => sub {
+    my $orig = shift;
     my $this = shift;
     for ( my $i = 1 ; $i <= scalar @test_comma_v ; $i++ ) {
         my $f = "$Foswiki::cfg{DataDir}/TestCases/SearchTestTopic$i.txt,v";
         unlink $f if -e $f;
     }
-    $this->SUPER::tear_down();
-}
+    $orig->($this);
+};
 
-sub list_tests {
+around list_tests => sub {
+    my $orig = shift;
     my ( $this, $suite ) = @_;
-    my @set = $this->SUPER::list_tests(@_);
+    my @set = $orig->( $this, @_ );
 
     $this->createNewFoswikiSession();
-    unless ( $this->{session}->webExists('TestCases') ) {
+    unless ( $this->session->webExists('TestCases') ) {
         print STDERR
           "Cannot run semi-automatic test cases; TestCases web not found";
         return;
@@ -207,7 +215,7 @@ sub list_tests {
     }
     $this->finishFoswikiSession();
     return @set;
-}
+};
 
 sub run_testcase {
     my ( $this, $testcase ) = @_;
@@ -224,21 +232,21 @@ sub run_testcase {
     $Foswiki::cfg{Plugins}{TestFixturePlugin}{Enabled} = 1;
     $Foswiki::cfg{Plugins}{TestFixturePlugin}{Module} =
       'Foswiki::Plugins::TestFixturePlugin';
-    $this->createNewFoswikiSession( $this->{test_user_login}, $query );
+    $this->createNewFoswikiSession( $this->test_user_login, $query );
     my ($topicObject) =
-      Foswiki::Func::readTopic( $this->{users_web}, 'ProjectContributor' );
+      Foswiki::Func::readTopic( $this->users_web, 'ProjectContributor' );
     $topicObject->text('none');
     $topicObject->save();
     $topicObject->finish();
-    my ($text) = $this->capture( $VIEW_UI_FN, $this->{session} );
+    my ($text) = $this->capture( $VIEW_UI_FN, $this->session );
 
     unless ( $text =~ m#<font color="green">ALL TESTS PASSED</font># ) {
         $this->assert(
             open( my $F, '>:encoding(utf8)', "${testcase}_run.html" ) );
         print $F $text;
         $this->assert( close $F );
         $query->delete('test');
-        ($text) = $this->capture( $VIEW_UI_FN, $this->{session} );
+        ($text) = $this->capture( $VIEW_UI_FN, $this->session );
         $this->assert( open( $F, '>:encoding(utf8)', "${testcase}.html" ) );
         print $F $text;
         $this->assert( close $F );

diff --git a/UnitTestContrib/test/unit/SerialiseTests.pm b/UnitTestContrib/test/unit/SerialiseTests.pm
@@ -6,12 +6,7 @@
 # initially they test the ancient Embedded code
 
 package SerialiseTests;
-use strict;
-use warnings;
-require 5.006;
-
-use FoswikiFnTestCase();
-our @ISA = qw( FoswikiFnTestCase );
+use v5.14;
 
 use Assert;
 use Foswiki;
@@ -20,23 +15,10 @@ use Foswiki::Plugin();
 use Foswiki::Func();
 use File::Temp();
 use Foswiki::AccessControlException();
-use Error qw( :try );
-
-sub set_up {
-    my $this = shift;
-
-    $this->SUPER::set_up();
-
-    return;
-}
-
-sub tear_down {
-    my $this = shift;
 
-    $this->SUPER::tear_down();
-
-    return;
-}
+use Moo;
+use namespace::clean;
+extends qw( FoswikiFnTestCase );
 
 sub skip {
     my ( $this, $test ) = @_;
@@ -98,7 +80,7 @@ sub test_SimpleMetaTopic {
     my $this = shift;
 
     my $meta =
-      Foswiki::Meta->new( $this->{session}, $this->{test_web}, 'TestTopic' );
+      Foswiki::Meta->new( $this->session, $this->test_web, 'TestTopic' );
 
     $meta->text("\n\n onceler \n \n\n \n\n\n");
     $meta->putKeyed( 'FIELD', { name => 'fieldname', value => 'meta' } );
@@ -111,8 +93,11 @@ sub test_SimpleMetaTopic {
 
     my $text = $meta->getEmbeddedStoreForm();
 
-    my $metaFromSerialised =
-      Foswiki::Meta->new( $this->{session}, $this->{test_web}, 'TestTopic' );
+    my $metaFromSerialised = Foswiki::Meta->new(
+        session => $this->session,
+        web     => $this->test_web,
+        topic   => 'TestTopic'
+    );
     $metaFromSerialised->setEmbeddedStoreForm($text);
 
     my $textAgain = $metaFromSerialised->getEmbeddedStoreForm();
@@ -126,15 +111,21 @@ sub test_SimpleMetaTopic {
 sub test_SimpleTopic {
     my $this = shift;
 
-    my $meta =
-      Foswiki::Meta->new( $this->{session}, $this->{test_web}, 'TestTopic' );
+    my $meta = Foswiki::Meta->new(
+        session => $this->session,
+        web     => $this->test_web,
+        topic   => 'TestTopic'
+    );
 
     $meta->text("Onceler\njumped");
 
     my $text = $meta->getEmbeddedStoreForm();
 
-    my $metaFromSerialised =
-      Foswiki::Meta->new( $this->{session}, $this->{test_web}, 'TestTopic' );
+    my $metaFromSerialised = Foswiki::Meta->new(
+        sesison => $this->session,
+        web     => $this->test_web,
+        topic   => 'TestTopic'
+    );
     $metaFromSerialised->setEmbeddedStoreForm($text);
 
     my $textAgain = $metaFromSerialised->getEmbeddedStoreForm();
@@ -148,8 +139,11 @@ sub test_SimpleTopic {
 sub test_SimpleTopicSave {
     my $this = shift;
 
-    my $meta =
-      Foswiki::Meta->new( $this->{session}, $this->{test_web}, 'TestTopic' );
+    my $meta = Foswiki::Meta->new(
+        session => $this->session,
+        web     => $this->test_web,
+        topic   => 'TestTopic'
+    );
 
     $meta->text("Onceler\njumped");
 
@@ -158,23 +152,22 @@ sub test_SimpleTopicSave {
     $meta->save();
     $meta->finish();
 
-    my $rawFirst =
-      Foswiki::Func::readTopicText( $this->{test_web}, 'TestTopic' );
+    my $rawFirst = Foswiki::Func::readTopicText( $this->test_web, 'TestTopic' );
 
     #remove the TOPICINFO
     $rawFirst =~ s/^%META:TOPICINFO\{.*?\}%\n//m;
 
     $this->assert_equals( $text, $rawFirst );
 
     my ( $newmeta, $t ) =
-      Foswiki::Func::readTopic( $this->{test_web}, 'TestTopic' );
+      Foswiki::Func::readTopic( $this->test_web, 'TestTopic' );
     $this->assert_equals( $text, $newmeta->text() );
 
     $newmeta->save();
     $newmeta->finish();
 
     my ( $three, $t3 ) =
-      Foswiki::Func::readTopic( $this->{test_web}, 'TestTopic' );
+      Foswiki::Func::readTopic( $this->test_web, 'TestTopic' );
     $this->assert_equals( $text, $three->text() );
 
     return;
@@ -187,35 +180,33 @@ sub test_Meta_CopyAll {
     my $query;
 
     my ( $meta, $text ) =
-      Foswiki::Func::readTopic( $this->{test_web}, 'MergeSave' );
+      Foswiki::Func::readTopic( $this->test_web, 'MergeSave' );
     $meta->text("Smelly\ncat");
     $meta->save();
     $meta->finish();
 
     #my $rawFirst =
-    #  Foswiki::Func::readTopicText( $this->{test_web}, 'MergeSave' );
+    #  Foswiki::Func::readTopicText( $this->test_web, 'MergeSave' );
 
-    ( $meta, $text ) =
-      Foswiki::Func::readTopic( $this->{test_web}, 'MergeSave' );
+    ( $meta, $text ) = Foswiki::Func::readTopic( $this->test_web, 'MergeSave' );
     $this->assert_equals( "Smelly\ncat", $text );
 
     # A saves again, reprev triggers to create rev 1 again
     $query = Unit::Request->new(
         initializer => {
             action => ['save'],
             text   => ["Sweaty\ncat"],
-            topic  => [ $this->{test_web} . '.MergeSave' ]
+            topic  => [ $this->test_web . '.MergeSave' ]
         }
     );
-    $this->createNewFoswikiSession( $this->{test_user_login}, $query );
+    $this->createNewFoswikiSession( $this->test_user_login, $query );
     my $UI_FN ||= $this->getUIFn('save');
-    $this->captureWithKey( save => $UI_FN, $this->{session} );
+    $this->captureWithKey( save => $UI_FN, $this->session );
 
     #my $rawSecond =
-    #  Foswiki::Func::readTopicText( $this->{test_web}, 'MergeSave' );
+    #  Foswiki::Func::readTopicText( $this->test_web, 'MergeSave' );
 
-    ( $meta, $text ) =
-      Foswiki::Func::readTopic( $this->{test_web}, 'MergeSave' );
+    ( $meta, $text ) = Foswiki::Func::readTopic( $this->test_web, 'MergeSave' );
 
     # Foswiki::UI::buildNewTopic explicitly makes sure there is
     # one \n at the end of each text submitted

diff --git a/UnitTestContrib/test/unit/StoreImplementationTests.pm b/UnitTestContrib/test/unit/StoreImplementationTests.pm
diff --git a/UnitTestContrib/test/unit/StoreTests.pm b/UnitTestContrib/test/unit/StoreTests.pm
diff --git a/core/lib/Foswiki.pm b/core/lib/Foswiki.pm
@@ -51,6 +51,8 @@ use Foswiki::Configure::Load ();
 use Scalar::Util             ();
 use Foswiki::Exception;
 
+#use Foswiki::Store::PlainFile ();
+
 # Item13331 - use CGI::ENCODE_ENTITIES introduced in CGI>=4.14 to restrict encoding
 # in CGI's html rendering code to only these; note that CGI's default values
 # still breaks some unicode byte strings
@@ -320,8 +322,9 @@ has store => (
 has _baseStoreClass => (
     is      => 'rw',
     clearer => 1,
-    default => 'Foswiki::Store::PlainFile',
-    isa     => sub {
+
+    #default => 'Foswiki::Store::PlainFile',
+    isa => sub {
         ASSERT( defined( $_[0] ), "Foswiki::_baseStoreClass cannot be undef" );
     },
 );
@@ -1134,8 +1137,6 @@ sub BUILD {
     # are being processed.
     $Foswiki::Plugins::SESSION = $this;
 
-    # SMELL XXX Test to avoid circular dependencies. Dangerous!
-    Scalar::Util::weaken($Foswiki::Plugins::SESSION);
     ASSERT( $Foswiki::Plugins::SESSION->isa('Foswiki') ) if DEBUG;
 
     # construct the store object
@@ -2368,7 +2369,7 @@ See http://blog.fox.geek.nz/2010/11/searching-design-spec-for-ultimate.html for
 
 =cut
 
-sub load_package {
+sub _package_loaded {
     my $fullname = shift;
 
     # See if package is already defined in the main symbol table.
@@ -2377,7 +2378,13 @@ sub load_package {
     no strict 'refs';
     my $pkgLoaded = defined $namePref->{"${nameSuff}::"};
     use strict 'refs';
-    return if $pkgLoaded;
+    return $pkgLoaded;
+}
+
+sub load_package {
+    my $fullname = shift;
+
+    return if _package_loaded($fullname);
 
     my $filename = File::Spec->catfile( split /::/, $fullname ) . '.pm';
     #

diff --git a/core/lib/Foswiki/Meta.pm b/core/lib/Foswiki/Meta.pm
@@ -149,7 +149,9 @@ our $CHANGES_SUMMARY_PLAINTRUNC = 70;
 has session => (
     is      => 'ro',
     clearer => 1,
-    isa     => Foswiki::Object::isaCLASS( 'session', 'Foswiki', noUndef => 1 ),
+
+    #weak_ref => 1,
+    isa => Foswiki::Object::isaCLASS( 'session', 'Foswiki', noUndef => 1 ),
 );
 has web => (
     is        => 'rw',

diff --git a/core/lib/Foswiki/UI/Save.pm b/core/lib/Foswiki/UI/Save.pm
@@ -149,7 +149,7 @@ sub buildNewTopic {
         $text = '' if $query->param('newtopic');    # created by edit
         $topicObject->text($text);
 
-        foreach my $k ( keys %$ttom ) {
+        foreach my $k ( keys %{ $ttom->metaData } ) {
 
             # Skip internal fields and TOPICINFO, TOPICMOVED
             unless ( $k =~ m/^(_|TOPIC)/ ) {
@@ -158,7 +158,7 @@ sub buildNewTopic {
 
             # attachments to be copied later
             if ( $k eq 'FILEATTACHMENT' ) {
-                foreach my $a ( @{ $ttom->{$k} } ) {
+                foreach my $a ( @{ $ttom->metaData->{$k} } ) {
                     push(
                         @attachments,
                         {