We've made some tweaks to the Ragnarok Online installer file, and installations of Ragnarok Online Renewal using the installer source from
http://www.playragnarok.com/downloads/clientdownload.aspx
(we recommend the torrent)
should work. Download the "crosstie" file here, open in CX Games, choose your downloaded Ragnarok .msi file as the installer (using "Choose installer file"), and click "install".
When the Ragnarok installation is complete, your initial patching attempt will probably fail. Close Ragnarok, and then go to Crossover's Programs menu (or Windows Games, if you're on Linux), and launch from the "Ragnarok Renewal" item, rather than regular "Ragnarok". This should allow you to patch successfully. Thereafter you should be able to launch and patch from the "Ragnarok" or "Ragnarok Renewal" launch item.