Problem with updating wordpress

Hello. I have installed a fresh copy of wordpress on my hosting account, via the auto installer supplied in the cPannel of the hosting platform I am using. It was successfully installed with the version 4.0.1

Now, here starts the problems. I am trying to update wordpress from version 4.0.1 to the latest version, 4.3.1. However, everytime I’m trying to do so, either with the automatic update or trying to update it manually, I receive a 500 Internal server error, thus failing the update.

In the same manner, every time I try to update the themes to their latest version(I only have installed the Twenty fifteen, fourteen and thirteen themes) I get an error, displaying that my website is going under
“maintenance” for a few minutes, making it unusable for around 10 minutes. When i return to the website the updates weren’t applied.

A few more info about my problem:

– I am running no plugins at the moment of trying to update(I deleted all of them, they are not just deactivated).
– I am using Hostinger as my host.
– I have the website linked to my .com domain name.

Thank you in advance for any help you might have, I will do my best to supply any more info needed to help me fix the problem.

P.S: I have also sent a support ticket to my hosting company, but while they answer I decided to try my luck here.