If they use iCloud (or OneDrive/DropBox or any other cloud storrage) to save all their files, it's possible none of the files are actually saved locally to the computer (they exist on the cloud but create 'fake' shortcuts to make it look like they're on the computer and easily download them).  If this is the case I've a few ideas of things they could try.
- They could try opening the Maple file by right clicking to download before opening it. 
- They could set their iCloud to always keep an offline copy of everything. There's some information on this here.
- I'm not a Mac user myself but there may be a way to keep a specific file or specific filetype stored locally too. I believe this exists for OneDrive so it may exist for iCloud too.
- I wouldn't recommend it, but disabling iCloud for the files would work too - but iCloud has some good features such as lost file recovery so it's a pretty good things to have to keep a backup of work especially if everything gets backed up to it.

If the issue isn't iCloud then I'd see if the files could be opened if they're saved to a folder on the desktop

Our developers are currently working to improve this in a future version of Maple. If you contact support@maplesoft.com we should be able to help you.

If it's a Maple/syntax issue where you're running into a problem someone may be able to provide some guidance if you show what you've done so far.

You can attach a Maple worksheet using the green arrow when you're writing a post/comment.
 

If it's a matter of understanding the question then your course notes or textbook should have some background. This Wikipedia page has information on Secret Sharing:
https://en.wikipedia.org/wiki/Secret_sharing 
A starting point may be finding where the planes intersect. 

You may be able to view them individually if you assign it to a list with

eq:=A:-GetEquations(...):

you can then index the list with

daes:=eq[1]:

to see the daes.The list of daes can be further indexed to see them one at a time.

daes[1];

If the equations are still too large to view you can try the lprint function which will display them as plain text code. For example:

lprint(daes[1]);

@gkokovidis  An updated version of the Syrup package is also available on the Maple Cloud now. 

@zohar I'm not sure what Maple 2016 looks like with the high contrast settings, but setting it that way on my computer for Maple 2019 (with the font style) looks like this:

and similarly for Maple 2020:

The context panel (the panel on the right) wasn't available in Maple 2016 and appears to keep the black background but the palettes on the left are still lighter. I also noticed that the style set I sent you before doesn't work for 1D Math (red code). If you use code often I'd recommend using this style set instead. 

High_Contrast_Style_Set.mw

@tomleslie It looks like this has been added in Maple 2020

Download 3D_Graph_vertex_edge_colour.mw

The cursor being italic likely indicates that you're in 2D Math mode. You can find some information on the difference between 2D Math and classic Maple Code here. Is this what you mean?

If you want Maple 2019's input to look a bit more like Maple 8 you can find instructions on how to do that here.

This can be solved easily in Maple just by writing out the equations and initial conditions and using pdsolve.

pde.mw

If you don't have a copy you can download a free trial from here:

https://www.maplesoft.com/products/maple/free-trial/

Try changing the term 

2 k alpha[1] alpha[2]0 

to 

2 k alpha[1]*alpha[2]*0

The error could be caused by the lack of a space, but putting the opperators there explicitly seems to allow the code to start evaluating.