I note the following
- dual boot windows
- manjaro uses btrfs
btrfs is a filesystem which is gaining a lot of momentum due to the features it provides.
Upon filesystem damage, btrfs will lock the file system, to prevent further damage.
To recover you will need to boot from a live system. Please see Basic Manjaro Linux Recovery for instructions on how to reach the damaged filesystem.
Then see the relevant sections on Manjaro Wiki
See → Btrfs - Maintenance
See → Btrfs - Solving Problems