How to define/modify folder for 'open files'?


since I moved my work from laptop A with Jabref 2.11 to laptop B with Jabref 4.3.1 installed I am no longer able to use right-click-function ‘Open file’ because it is greyed out.
My library consists of tons of scientic paper entries that all have Bibtexkeys. How and where can I define the option to modify the folder in that Jabref can find the corresponding pdf files?

Thanks in advance.

You can specify the folder under File > Library properties. Also make sure that the file pattern is correct (in the Preferences).