You must have something assigned to x or y, I have no problems.  Use restart before executing your statements.

Thanks for the replies. 

Funny the command isolate doesn't have the ability to isolate multiple variables or accept arguments like integer etc...

@Les Go to Start Menu -> Control Panel -> System and Security under Windows update click the View installed updates .. you will have a list of updates.  Right click on the security patch and option will be given to uninstall.

Find KB4034664 and uninstall it.  Everything should work fine after that .. (hopefully) if still problem then remove superseeding patches one at a time to see if problem goes away.

@phil2 good to know I correctly postulated a windows update problem as one of my original suggestions.

listplot visually shows some pattern but not as a whole.  I don't think there is enough information to deduce future values.

You mentioned it was working at one point?  you said "I was able to move, open, etc. any .mw file for over a year, then a couple of days ago the files started to distort."  I'm certain you were talking about 2015.0, correct?  This tells me Maple 2015 was working and so it had to be either a Maple update or a Windows update.  A re-installation of Windows I believe would have incorporated any new updates so wouldn't have really changed anything, the restore was your best option to test if updates were the issue(of course not possible now).  

I currently don't have Maple 2015 at my fingertips so I can't verify right now.  It might be possible for me to check on the weekend unless someone else has a solution. 

**edit added** I just read somewhere that someone was having a display problem with Maple 17 and they upgraded to Windows 8.1 and the problem went away which suggests that Windows is the problem.

I have not experienced the issue but I offer an idea.

You mentioned it was working up until a couple of days ago (2 days prior to Aug 15) so if you can recall what other softwares you had installed during that time, they may be causing the issue.  It could also be a windows update causing the issue. 

I would suggest using system restore and restore to a point before you believe the time this issue started occuring (hopefully a point exists).  This has usually gotten me out of a bind a couple of times.  Hopefully that works.

@Preben Alsholm .. Well then, amateurs would make the suggestions and leave it to the experts to implement it.  I used Maple 12 as an example.  But generally patches would be made on the version just before the most recent release ie Maple 2016

@Preben Alsholm that should work as a good workaround, thanks

Is it because you are using matrix instead of Matrix?

Haven't looked into it but there has to be a workaround for this. 

I haven't seen a dot 3 release since Maple 10 so I would hesitate to actually see Maple 2018.3.  I like the workaround fixes since they help the user immediately instead of having to wait for a fix.

Yes of course use convert as I mentioned in first post. 

Re:MMA - sorry I don't use MMA but I thought it's default was degrees, thanks for pointing that out.

@Fabio92 nope, you can't change the way + operates.

Historically students enter a value in degree format almost automatically.  It's more of a preference I guess.

If it was implemented I don't believe it would be an issue.  The default would be radians and Maple would resort to that if opening older worksheets.  However in newer worksheets Maple would embeded the setting into the saved worksheet to tell Maple what to set it at next time it opened.  It' s no different when starting an AutoCAD document - upon opening a new workspace it asks you the type of formats you want to work in, and you don't have to worry about the settings next time you open the document - it's already set up.

@Markiyan Hirnyk obviously CAS.