cannot deploy Portfolio example

Pushing Site
persisting MyPortfolio [failed]
Resource invalid: metafields_schema Invalid metafields_schema: "767: unexpected token at ''". Check it out on http://jsonlint.com
Resource invalid: metafields_schema Invalid metafields_schema: "767: unexpected token at ''". Check it out on http://jsonlint.com
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_coal-1.0.0/lib/locomotive/coal/resources/concerns/request.rb:36:in do_request' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_coal-1.0.0/lib/locomotive/coal/resources/concerns/request.rb:15:in put'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_coal-1.0.0/lib/locomotive/coal/resources/current_site.rb:13:in update' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_site_command.rb:25:in persist'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_base_command.rb:34:in block in _push' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_base_command.rb:30:in each'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_base_command.rb:30:in _push' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_base_command.rb:25:in block in _push_with_timezone'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/activesupport-4.2.11.1/lib/active_support/core_ext/time/zones.rb:48:in use_zone' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_base_command.rb:24:in _push_with_timezone'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_base_command.rb:18:in block in push' /home/jerome/.rvm/gems/ruby-2.6.3/gems/activesupport-4.2.11.1/lib/active_support/notifications.rb:166:in instrument'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_base_command.rb:47:in instrument' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_base_command.rb:16:in push'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_sub_commands/push_base_command.rb:12:in push' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_command.rb:55:in block in _push'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_command.rb:84:in block in each_resource' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_command.rb:77:in each'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_command.rb:77:in each_resource' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_command.rb:54:in _push'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_command.rb:41:in push' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/commands/push_command.rb:31:in push'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon.rb:73:in push' /home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/lib/locomotive/wagon/cli.rb:308:in deploy'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/thor-0.19.4/lib/thor/command.rb:27:in run' /home/jerome/.rvm/gems/ruby-2.6.3/gems/thor-0.19.4/lib/thor/invocation.rb:126:in invoke_command'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/thor-0.19.4/lib/thor.rb:369:in dispatch' /home/jerome/.rvm/gems/ruby-2.6.3/gems/thor-0.19.4/lib/thor/base.rb:444:in start'
/home/jerome/.rvm/gems/ruby-2.6.3/gems/locomotivecms_wagon-2.0.1/bin/wagon:12:in <top (required)>' /home/jerome/.rvm/gems/ruby-2.6.3/bin/wagon:23:in load'
/home/jerome/.rvm/gems/ruby-2.6.3/bin/wagon:23:in <main>' /home/jerome/.rvm/gems/ruby-2.6.3/bin/ruby_executable_hooks:24:in eval'
/home/jerome/.rvm/gems/ruby-2.6.3/bin/ruby_executable_hooks:24:in `