Directory is not writable on shared hosting

I created an app with Yii2 Advanced template.

I have hosted it on a SHARED HOSTING SERVER.

It has been working fine,

but recently it is down. it keeps displaying an error:

Invalid Configuration – yii\base\InvalidConfigException

‘The directory is not writable by the Web process: /home/tryjambc/public_html/assets’

My webhost have been trying to fix it, no luck yet!

What could be causing this issue ?

They have done: chmod 777 /home/nicjccom/public_html/assets

What else do I ask my WebHost to do, in order to fix it ?

Thanks in advance !!

Its giving us Sleepless Nights!!!

Do not double post! :(

And do not use all caps titles either.