Crash after removing wwise plugin

Hopefully someone can help us here.

We used the Wwise Plugin for our sound but we want to remove it now.

Replace every sound with the build-in sound in the engine works except from one Blueprint.

There was one component (this AkComponent) which I removed in the Blueprint before removing the plugin, but everytime this Blueprint takes action (when i´m testing the game) it force-closes the whole engine.

Is there a way to remove this part of the blueprint which cannot be seen in the standard editor? maybe a line of code somewhere?

The crashing engine brings us the following error:

Fatal error: [File:D:\Build++UE4+Release-4.15+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\LinkerLoad.cpp] [Line: 2442]
Failed import: AkComponent AkComponent /Game/Blueprints/Pickups/SpeedUpTunnel.SpeedUpTunnel_C:Ak_GEN_VARIABLE (file …/…/…/…/…/…/projects/droneracer/Content/Blueprints/Pickups/SpeedUpTunnel.uasset)

Hopefully someone can help us.