Hey Divital -
The Red Triangle just means that the VFX Thumbnail in the Content Browser does not match the Effect anymore. It will remain until you update the VFX Thumbnail and will reappear if you edit the effect again. The crash reporter is logging the report now I may not get access to it before Monday.
Are you getting the crash on all types of saves or just with the Cascade save? In other words, are you crashing from the Level Save button in the Main Viewport’s toolbar, the Save All button in the Content Browser or the Save button in Cascade? Is this crash limited to your one project? If so and if you can narrow down the exact asset, try making a new project Blank with no content in it and then copy the *.uasset and *.umap files over into the new Content folder via Windows Explorer and test the save function again.
Eric Ketchum