Changes to the AutoCAD application programming interfaces (APIs) occur with each
new release, but might not require you to recompile or change existing custom programs
so they work in the latest release.

With each new release, you should retest all your custom and third-party applications.
Any programs that utilize commands or system variables should be reviewed to ensure
the command string (such as command name, options, and values) is still valid. Also
verify that no deprecated commands or system variables are being used.

The following outlines some additional changes that could affect the use of custom
programs developed for an AutoCAD-based product prior to AutoCAD 2016:

• Scripts and Action Macros – No changes should be needed.
• AutoLISP – No changes should be needed.
• ActiveX/VBA – Programs that assign a password to a drawing must be modified and any program that
  uses the SendCommand method should be reviewed to see if the SendCommand method should be changed to use the PostCommand method that was introduced with AutoCAD 2015-based products. Programs developed for
  AutoCAD 2014-based products and earlier should also be reviewed and updated for proper
  64-bit compatibility.
• .NET – Programs that assign a password to a drawing or utilize render presets must be
  modified, and those that were developed for AutoCAD 2014-based products and earlier
  must be recompiled.
• ObjectARX – Programs that assign a password to a drawing or utilize render presets must be
  modified, and those that were developed for AutoCAD 2014-based products and earlier
  must be recompiled.
• JavaScript – No changes should be needed.

Learning AutoCad

th each new release, you should retest all your custom and third–party applications. Any programs that utilize commands or system variables should be  …application programming interfaces (APIs) occur with each … With each new release, you should retest all your custom and third–party  …application programming interfaces (APIs) occur with each new release, but might not require you to recompile or change existing …Third–party applications might need to be repurchased and in-house custom . NET and ObjectARX applications might need to be recompiled when upgrading.Application Compatibility Toolkit (ACT) is the Microsoft tool suite to test and understand application … When investigating application compatibility for third– party applications, it is important to … Custom Compatibility Fixes for Applications.