I installed Wings Of Liberty in "D:\Games\StarCraft II". I install all my games in the D: drive because that's my larger (2TB) storage drive. My C: drive is a smaller (128GB) SSD OS drive.
The game installed absolutely fine; no issues whatsoever.
Then I put in the disc for the expansion set and started to install Heart Of The Swarm. It picked up the "D:\Games\StarCraft II" as the folder where WoL was installed; however, after I click on "Agree", I get the following error:
Could not install.
Invalid installation options. Please try again.
... and it won't proceed with the installation!!
I don't get it!! It installed WoL absolutely fine in the same location; why can't it install HoTS? It's not telling me anything pertinent to help me resolve the issue.
I found a thread somewhere which had a similar error, but their issue was different - they had already played WoL and just wanted to install HoTS so they renamed their WoL folder and were able to install HoTS. I don't know if that's applicable to me because I have not played WoL yet -- so I still need that installed & working.
I have installed both these games in the past on a traditional "C:\Program Files\StarCraft II" structure and didn't have a problem. I Don't know why I'm having this issue now with HoTS.