Category: Quartus® Prime
Tools: Quartus® Prime
device:-

Check the version of Quartus Prime. (Quartus Prime Help menu ⇒ About Quartus Prime)
If the device file (*.qdz) is installed in the environment where the update file is additionally installed,
An Internal Error has occurred due to a mismatch in the order of installation.

for example
Quartus Prime Standard Edition 18.1.1 Build 646 (environment with Update 1 additionally installed to ver.18.1)
For example, if you additionally installed the Cyclone 10 LP device file (cyclone10lp-18.1.0.625.qdz).

To avoid this, download the Update file from the Quartus Prime Standard Edition main unit,
and uninstall the device file (*.qdz).
After that, install the device file (*.qdz) again and additionally install the Update file.

Detailed steps are below.

<How to uninstall the device file>
Follow the steps below to uninstall the device files.

1. From Windows 10 Control Panel > Programs and Features,
Select Quartus Prime Standard Edition xx.xxxxx and the Uninstaller will launch.

2. Select [Individual components] from Uninstall Mode
Check the target device to uninstall from the Devices category in the Select Components To Uninstall list.
Run the uninstall.

Then follow the steps below to uninstall the update files.

<How to uninstall the update file>
In Windows OS "Programs and Features" (in Control Panel)
Specify the uninstaller for Quartus Prime Standard Edition xx.xxxxx and run the uninstallation.

<Installing device files and update files>
1. Make sure you have successfully uninstalled and have a plain version of Quartus Prime.

2. From the Windows 10 Start Menu Intel FPGA xx.xxxxx Standard Edition folder
Start Device Installer, specify the device file (*.qdz), and perform additional installation.

(* If possible, perform the same work as when Internal Error occurred,
Make sure that no Internal Error occurs in this tool environment. )

3. Install additional update files.