Superseded by the 1.0.1.140-beta.1 portal-fork test

Use TESTING_1.0.1.140-beta.1.md. It covers both supported fork candidates.

Correction: the user's installed Seamless file exactly matches current published CurseForge file 9218525 (displayed 10.0.0, internal version/filename 1.0.0). The startup failure applies only to older file 8937394. The earlier recommendation to avoid the current download was incorrect.