Hi everybody,
I’m experiencing the same issue. My students are studying the VIEWBASE command, so I’ve had the chance to observe this problem many times on different computers. It also occurs in the latest version, AutoCAD 2027.
There is a recent article from Autodesk Support that addresses this issue:
https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/VIEWBASE-returns-e...
It partially resolves the problem, but not always. The standard solution is to run a custom AutoCAD installation and manually select the Inventor Interoperability Extension. In some cases, this works: the package downloads successfully and the installation starts automatically. In others, the download completes successfully, but the installation does not start; instead, a “New Package” shortcut appears on the desktop. When launched as an administrator, the installation then completes successfully. However, in most cases with AutoCAD 2026/2027, the launching of the "New Package" either does nothing or displays the message “Another installation is in progress.” As a workaround, we restart the computer, locate the installation folder (…\Autodesk\…\WI), open the most recently created subfolder (named with a 20-digit number), and run the file INVINTEROP_202X.exe as an administrator. This usually works.
Does anyone know a more reliable solution?