newest axlsx ( 3.0.0.pre ) gem only support to rubyzip ~> 1.2. It is not support to redmine 4.2.1.

[Thi Quy Bui]

Redmine 4.2.1 use rubyzip ~> 2.3.0 , because of the drop support of Ruby 2.3.

But, newest axlsx gem -3.0.0.pre - require dependent gem:  rubyzip ~> 1.2 .

Please help us to build other version that support rubyzip ~> 2.3.0 . 

Thank you so much.