Class 'Category' not found

[mcbole62]

Yesterday after a move from a shared host to a VPS my site was getting the following error in the err_log:
 

 

[08-Jul-2017 20:08:04 US/Eastern] PHP Fatal error: Class 'Category' not found in /home/hobbywo1/public_html/Store/modules/blocktopmenu/blocktopmenu.php on line 480

 

I was also getting a not being able to find a config file.  I found that somehow during the migration, the config got renamed to config-0 so I set it back to config and I was able to get the back office running.  I went into modules and ran the latest 1 click upgrade which went successfully.   But now this morning I am getting a few reports of the site not working for folks.   And I'm getting a whole host of these errors revolving around the Class 'Category" not found.

 

[09-Jul-2017 01:53:00 US/Eastern] PHP Fatal error: Class 'Category' not found in /home/hobbywo1/public_html/Store/classes/Product.php on line 509

 

[09-Jul-2017 01:55:04 US/Eastern] PHP Fatal error: Class 'Category' not found in /home/hobbywo1/public_html/Store/classes/Product.php on line 509

 

[09-Jul-2017 01:55:50 US/Eastern] PHP Fatal error: Class 'Category' not found in /home/hobbywo1/public_html/Store/classes/Product.php on line 509

 

[09-Jul-2017 01:59:22 US/Eastern] PHP Fatal error: Class 'Category' not found in /home/hobbywo1/public_html/Store/controllers/front/CategoryController.php on line 105

 

[09-Jul-2017 02:00:39 US/Eastern] PHP Fatal error: Class 'Category' not found in /home/hobbywo1/public_html/Store/classes/Product.php on line 509

 

plus a lot more....

 

So my question is where can I find this Category file that appears to me missing ?  I looked in the Class folder and I have a Category.php file.   I've read about a class_index.php file but I don't see that anywhere. 

 

Here is some info on the site:
PrestaShop version 1.6.1.15

Shop URL http://www.hobbyworld-usa.com/Store/

Current theme in use default-bootstrap

 

And I'm also seeing this:
Required parameters OK

Optional parameters Please fix the following error(s)

• Allow the PHP fopen() function on your server.   Does this have anything to do with these errors ?

Thank you...

 

[Scully]

double post?