Nil value issues

[seascoot]

Using Ubuntu 18.04.2 LTS
If I run the last release in ruby-2.6.3 I get

/home/*****/.rvm/gems/ruby-2.6.3/gems/stripe-iiftoqbo-0.1.4/lib/ofx.rb:44: warning: BigDecimal.new is deprecated; use BigDecimal() method instead.

An IFF file is generated with header but no data.

In ruby-2.1.0 in an attempt to avoid the deprecation issue I get:

/home/*****/.rvm/gems/ruby-2.1.0/gems/stripe-iiftoqbo-0.1.4/lib/ofx/transaction.rb:11:in `initialize': no implicit conversion of nil into String (TypeError)
        from /home/clive/.rvm/gems/ruby-2.1.0/gems/stripe-iiftoqbo-0.1.4/lib/ofx/transaction.rb:11:in `new'
        from /home/clive/.rvm/gems/ruby-2.1.0/gems/stripe-iiftoqbo-0.1.4/lib/ofx/transaction.rb:11:in `trnamt='
        from /home/clive/.rvm/gems/ruby-2.1.0/gems/stripe-iiftoqbo-0.1.4/lib/stripe-iiftoqbo.rb:159:in `block (2 levels) in to_qbo'
        from /home/clive/.rvm/gems/ruby-2.1.0/gems/stripe-iiftoqbo-0.1.4/lib/ofx.rb:49:in `transaction'
        from /home/clive/.rvm/gems/ruby-2.1.0/gems/stripe-iiftoqbo-0.1.4/lib/stripe-iiftoqbo.rb:157:in `block in to_qbo'
        from /home/clive/.rvm/gems/ruby-2.1.0/gems/stripe-iiftoqbo-0.1.4/lib/stripe-iiftoqbo.rb:156:in `each'
        from /home/clive/.rvm/gems/ruby-2.1.0/gems/stripe-iiftoqbo-0.1.4/lib/stripe-iiftoqbo.rb:156:in `to_qbo'
        from /home/clive/.rvm/gems/ruby-2.1.0/gems/stripe-iiftoqbo-0.1.4/bin/stripe-iiftoqbo:58:in `<top (required)>'
        from /home/clive/.rvm/gems/ruby-2.1.0/bin/stripe-iiftoqbo:23:in `load'
        from /home/clive/.rvm/gems/ruby-2.1.0/bin/stripe-iiftoqbo:23:in `<main>'
        from /home/clive/.rvm/gems/ruby-2.1.0/bin/ruby_executable_hooks:24:in `eval'
        from /home/clive/.rvm/gems/ruby-2.1.0/bin/ruby_executable_hooks:24:in `<main>'

I cannot figure out what is returning the nil value that the code is unable to handle. Could this be due to a change in Stripe's IIF format?