Hello Jake, and welcome to the Forums!
"Closing error messages allows users to use AutoCAD 2017.
If you disconnect from the Internet, then start the program, and then reconnect to the Internet, error messages do not show up."
Can you please check to see if the above will stop the error messages, even if it is only temporarily?
I have also found references to similar errors that were browser related:
"This ended up being that IE's document mode was being defaulted to IE7 Standards. This was due to the compatibility mode being automatically set to be used for all intranet sites (Tools > Compatibility View Setting > Display Intranet Sites in Compatibility View)."
Please check this setting and change it to see if the errors continue.
"Older IE versions (IE7 and IE 8) show following error."
Please check your version of IE and let me know what version you are using.
Also, I have a couple of other questions:
1. What OS are you using?
2. What version of Java do you have installed on your system?
3. Since only two of the five systems with AutoCAD 2017 are having issues, can you think of any differences between the two systems and the 3 that are not experiencing the issue? Maybe things like whether or not the users have Admin privileges or not, if the software was installed differently on the 2, or perhaps they are on a different network or subnet should be considered.
I know that seems like a lot, but sometimes the answer lies in a small detail.
I look forward to your reply.
Steve Tamplen
Technical Support Specialist