Contao Backend Administrator page broken

[zzeroda]

Today I found out one of the website I managed is suddenly lost the layout/styling.
From the login page to all page inside the backend are messed up.
I check the source whether the css or js assets is missing or not, apparently the css is missing.
then I uploaded a new one from the backup folder, unfortunately it's only work for the login page. all the pages after login is messed up without the styling.

This is how it looks:

ss.jpg

does anyone know how to fix this issue?

[Spooky]

Execute the Contao Check on your server.

[zzeroda]

This is what I have from the contao check :

Missing files :
.htaccess.default

is that a required file?

[zzeroda]

I simply tried to upload the .htaccess.default file that I got from contao core file on github, but now the contao check stated the .htaccess.default is corrupt,
what is the meaning if this indication anyway?

[Spooky]

No that's fine. But did the check show any problems on its main page? I didn't mean the validation.

[zzeroda]

This is the screenshot of the check :
Screen Shot 2017-01-17 at 14.39.10.png

The frontend runs well and no problem, only the backend that is messed up with the styling, I sill able to access the features.

[Spooky]

This is the screenshot of the check :
Screen Shot 2017-01-17 at 14.39.10.png

As you can see your hosting environment is not correctly configured. The PHP process is not allowed to create files. This is why the assets cannot be generated.

[zzeroda]

As you can see your hosting environment is not correctly configured. The PHP process is not allowed to create files. This is why the assets cannot be generated.

Ah I see, but since I used shared hosting, is there any way to solve those issues from my side?

[Spooky]

The access rights of your files may be are not set up correctly. You should contact your Hoster and ask him to fix this problem for you.