HDL Designer version is 2015.1b and Altera Quartus is 18.0.0.
Yesi I have compiled all the Altera libraries and added both in modelsim.ini and in HDL Designed as 'Downstream Library'.
HDS 2015.1b does not support Altera 18.0 as mentioned in its release notes
Also, I believe Intel/Altera has discontinued MegaWizard as of v14.1
So I'd recommend to upgrade to HDS 2018.2 (shipped earlier this month) and switch to Quartus Prime IP's
If you prefer to use Altera Megawizard in particular, you might want to check out knowledge base article MG575480 on "support.mentor.com" or contact Mentor Customer Support to help you with the setup
Thanks for the information. I will check it with the latest version.