When trying to open an InDesign template file to create some artwork my InDesign is saying that it cannot be opening and I must update my plugins, or upgrade my file. I am running InDesign 5.5 and I'd say the file is a newer version but I should still be able to work with it.
It has most likely been saved in a newer version then ID5.5 and as such you will not be able to open it. ID files have never been backwards compatiable (opening a newer file in an older version). You could always download the trial version of IDCC2014 and export it as an IDML file to use in ID5.5.