I'm placing anchored objects throughout a document and nearly every time I open the anchored objects settings to customize placement, the whole file crashes. It's crashed at least a dozen times in the last 20 minutes.
This has rarely ever happened before - how can i fix it?
Is this happening with just the one document or with every document that you try? If it is just the one document then you could try exporting it as an IDML file (File>Export>IDML). Then open that document in your version of InDesign and resave it as an InDesign file. This process can remove some forms of corruption from a file. Hopefully, that is all it will take.
If there is still a problem please make sure that you provide the version of InDesign and operating system that you are using.
Sorry to hear about your experience. In addition to the helpful response shared by Bill, please try following the troubleshooting steps shared on this community post to fix the unexpected behavior in the InDesign.