Porto Theme Version 3.6.4 - Fatal Error: Call To a Member Function Put_Contents() on Null

Dear Gents,
I am a purchaser of the Porto Theme since the version 3.2 all the way through to the version 3.6.3. All was well and there was no updating issues at all until this version 3.6.3 one. I use this Porto Theme on my WordPress website version 4.8.1 and WooCommerce 3.1.1.

With the latest Porto Theme update version 3.6.4, a serious problem has arised: it completely crashes my website and instead of displaying it correctly, the following sentence appears:
Fatal error: Call to a member function put_contents() on null in /home/xxxxx596/public_html/wp-content/themes/porto/functions.php on line 283

I tried to install this latest 3.6.4 update using the Envato installed plugin in the back-end of my WordPress site (as usual) with no success. The same aforementioned sentence appears.

I restored it three times during the latest two weeks.
It is odd, as I have never experienced this problem before!
I have always succeed with the previous versions.
It looks like there is a corrupted item on the line number 283 of the Porto Theme Functions.PHP and I do not have a clue how to sort this issue.

My website hosting provider said this file is corrupted. They requested me to get in touch with the Porto Theme team. They say they can do nothing to assist me in this regard.

Could you please kindly conduct an investigation and see what you can do about it?
If possible, a step-by-step solution procedure you send me would be great. If required, I can send you the entire Porto Functions.php code so you can examine it closely.

I appreciate your response, advice and instructions in advance.

Hello,

This is a community forum. Support for Porto (WordPress) is available here:

Cheers!

Dear Herbert,I appreciate your quick response with relevant info.
Thank you a lot for that!
Cheers!
Mario Lopes