Lost access to internal storage after rooting a Huawei G630. topic

So, after rooting my Huawei G630, i lost access to internal storage via the phone. I can access it via the PC.

- Rooted with towelroot
- Can acess internal storage with PC
- Can access internal storage with Root Explorer and i see my files
- Can't acess internal storage with a standard file manager. The directory is empty. Other apps say "no SD card inserted", and other say "Failed to save".
- Don't have a SD Card inserted.

Probably some stupid mounting issue or perrmission issue. Need some advice what to do. Thanks!