Accessing NTFS Drive from 3rd Party Application

• Apart from the system partitions, an internal partition, i.e., a partition on a disk in the computer, is not mounted by default. To use such partition, it must first be mounted explicitly by clicking its icon in Files.
• Even then, sandboxed applications may not be able to access the partition. Your applications likely are installed as snap packages. This is a new packaging format that "sandboxes" the applications: applications cannot anymore access any resource on your computer. Likely, both of your applications have been granted access to your home folder, but not to removable drives.

Either copy the files you want to work with to somewhere under your home folder for editing, or grant your applications permission to access removable drives, which are mounted under /media/. This can be done from within the Snap store.