“[SAVIOR]: Invalid Target Slot.”
Means the source slot class passed to the node is null.
I bet this is because the type renamed from USavior3 to USavior object.
Probably recreating your slot classes on asset browser would fix it when updating to latest version.
The types should never have a number suffix, I was forced to do it back then because of versioning problems in the Marketplace while several projects were still using Savior 2.
The last v3 on UE4.27 is the same version of plugin for Unreal 5, so there’s no “3” suffix after classes anymore.
I think for whatever reason the engine failed to redirect your slot classes from “Savior3” to “Savior” assets, and this crash happened. The code where the crash log points didn’t really change, your Blueprint should not compile when “[SAVIOR]: Invalid Target Slot.” assertion happens, but I think because the problem with redirector mentioned above, somehow it compiles… It’s important to “refresh all nodes” of the blueprint when changes like that is implemented.