I had the same issue happening to me, if anybody is facing this issue follow what was said by olnorton.
If for some reason you can't find Path there, create a string value by right clicking there, and naming it Path. Then copying your dragon age address from the explorer, then paste it there, the installer should work. Note: I tried this on the GOG version not sure with other versions that may have the problem.
Dragon Age: Origins game install not found (Toolset Installation)
in Builder Troubleshooting
Posted · Edited by kingkabab
I had the same issue happening to me, if anybody is facing this issue follow what was said by olnorton.
If for some reason you can't find Path there, create a string value by right clicking there, and naming it Path. Then copying your dragon age address from the explorer, then paste it there, the installer should work. Note: I tried this on the GOG version not sure with other versions that may have the problem.