Failed to launch MegaWizard™ Plug-In Manager. Custom PHY Intel® FPGA IP V18.1 could not be found in the specified library paths

In the Intel® Quartus® Prime Standard Edition software version 18.1, when you open the MegaWizard™ for editing, you may see error message “Failed to launch MegaWizard™ Plug-In Manager. Custom PHY Intel® FPGA IP V18.1 could not be found in the specified library paths”.

To work around this problem in the Intel® Quartus® Prime Standard Edition software version 18.1, follow the steps below.

1. Locate altera_xcvr_8g_custom_wizard.lst in your Intel® FPGA install directory.

    For Linux System:               /linux64/ip/altera/altera_xcvr_8g_custom/xcvr_generic

    For Windows System:        /ip/altera/altera_xcvr_8g_custom/xcvr_generic

2. Open altera_xcvr_8g_custom_wizard.lst, add following sentence in a new line after <ALIAS>Custom PHY v18.0</ALIAS> and save.    

    <ALIAS>Custom PHY Intel FPGA IP v18.1</ALIAS>

This problem is fixed beginning with the Intel® Quartus® Prime Standard Edition software version 19.1.