i'm New To This Forum and also New to Mailewizz Platform.

I'm Currently Experiencing This issue and it's Showing this Message and application isn't Loading :

CDbConnection failed to open the DB connection.
i'm receiving this afterwards also i'm getting this error now, the previous problem is solved automatically, now i've this, it's happening when i want to upload contacts to a list :

Error 400!
The CSRF token could not be verified.
This is simple, you try to upload a file that is larger than your PHP instance allows it, therefore the csrf token has no more room to pass.
The solution is to increase the PHP allowed upload size.
Besides "upload_max_filesize" , check/increase the value for the variable "post_max_size" also. In my case, the latter one was creating the same problem.