Forum Discussion
Try these links:
Pro version:
http://download.altera.com/akdlm/software/acdsinst/18.1/222/ib_installers/arria10-18.1.0.222.qdz
http://download.altera.com/akdlm/software/acdsinst/18.1/222/ib_installers/cyclone10gx-18.1.0.222.qdz
http://download.altera.com/akdlm/software/acdsinst/18.1/222/ib_installers/stratix10-18.1.0.222.qdz
Standard version:
http://download.altera.com/akdlm/software/acdsinst/18.1std/625/ib_installers/arria-18.1.0.625.qdz
http://download.altera.com/akdlm/software/acdsinst/18.1std/625/ib_installers/stratixv-18.1.0.625.qdz
http://download.altera.com/akdlm/software/acdsinst/18.1std/625/ib_installers/max10-18.1.0.625.qdz
http://download.altera.com/akdlm/software/acdsinst/18.1std/625/ib_installers/max-18.1.0.625.qdz
http://download.altera.com/akdlm/software/acdsinst/18.1std/625/ib_installers/cyclonev-18.1.0.625.qdz
http://download.altera.com/akdlm/software/acdsinst/18.1std/625/ib_installers/cyclone-18.1.0.625.qdz
http://download.altera.com/akdlm/software/acdsinst/18.1std/625/ib_installers/arriavgz-18.1.0.625.qdz
http://download.altera.com/akdlm/software/acdsinst/18.1std/625/ib_installers/arriav-18.1.0.625.qdz