Image upload failures after server PHP update

[gsimon]

            Briefly, here is my story: I have essentially inherited maintenance of a friend's website after the creating developer disappeared without a trace. Things had been working well until late this March when the hosting company upgraded PHP on the server. Many things became broken and I have fixed the majority of them.  However, the issue at hand has me perplexed. I am new to GetSimple and also somewhat unfamiliar with PHP. (I'm a retired Oracle DBA so I'm comfortable, just not familiar.) 
What happens is this: When the client attempts to upload images (.jpg files) the process errors out. The image file actually does land on the server, but the process indicates an error and the desired end result of a link inserted on a page does not happen. The server and application specs are below and images to show the error messages as well.  I'm at my wit's end with this and need to get it working for my friend/client.
Thanks in advance for any and all suggestions! 
Please, if you wish to see anything more such as snippets of code, php files, etc. Please let me know!
-george
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Linux web server
GetSimple Version 3.3.13
PHP Version 5.6.30
Item Manager V 1.6
Items Manager V 1.4 shown however I upgraded to 1.6 (?) 
Issues noticed after hosting company upgraded PHP. 
Ateempts to fix issue included various GS and related updates. 
(Virtually all GS and related areas were behind in releases.)
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