An option I didn't think of until now:
The config files are (almost) all text/xml format, so you can go to the config directory and do a search & replace on (2017) -> (2018) (checking each match makes sense to change, of course), if you need to bulk-edit a very large number of folder tabs, as well as find all the files that reference those paths by searching file content.
It's not something I'd recommend in general, or if you only have a small number of tabs to edit, but it is an option if there is a large number of them. Making a backup just before changing anything is also recommended.
For the config file locations, see here: How to backup or locate your Opus configuration (Simple)