For those users running into 500 error messages, it seems that malicious code may have been included in your site via "nulled" themes and plugins in WordPress. We published a security notice in our documentation to let the users know about it.
I suggest you follow the WordPress' security practices to keep your site secure and up-to-date. If you have any questions, do not hesitate to ask.
@cherngen_yang, our team continues checking the issues you ran into when resizing the disk.