Crash on 1.21.0 with MutableMap properties

[jrodbx]

Describe the bug
When trying to attach the app to LayoutInspector in Android Studio with an emulator, I noticed a crash.

The stack trace shows:

2026-01-30 15:32:43.556 27323-27323 com.creditgenie.app     com.creditgenie.app                  D  Segment: Tracking event 'Link Clicked' with params: {linkText=Sign In Link}
2026-01-30 15:32:43.604 27323-27323 AndroidRuntime          com.creditgenie.app                  E  FATAL EXCEPTION: main (Fix with AI)
                                                                                                    Process: com.creditgenie.app, PID: 27323
                                                                                                    java.lang.ClassCastException: kotlin.reflect.jvm.internal.KTypeImpl cannot be cast to kotlin.jvm.internal.TypeReference
                                                                                                    	at kotlin.jvm.internal.ReflectionFactory.mutableCollectionType(ReflectionFactory.java:107)
                                                                                                    	at kotlin.jvm.internal.Reflection.mutableCollectionType(Reflection.java:197)
                                                                                                    	at presentation.common.utils.cg_analytics.clients.SegmentAnalyticsClientImpl.trackEvent(SegmentAnalyticsClientImpl.kt:161)
                                                                                                    	at presentation.common.utils.cg_analytics.clients.SegmentAnalyticsClientImpl.createEvent(SegmentAnalyticsClientImpl.kt:83)
                                                                                                    	at presentation.common.utils.cg_analytics.CGAnalyticsLoggerImpl.logEvent(CGAnalyticsLoggerImpl.kt:91)
                                                                                                    	at presentation.common.utils.cg_analytics.CGAnalyticsLogger$DefaultImpls.logEvent$default(CGAnalyticsLoggerImpl.kt:27)
                                                                                                    	at creditgenie.presentation.signin_signup.ui.authlanding.AuthLandingScreenKt$AuthLandingScreenContent$5.invoke$lambda$9$lambda$8$lambda$7$lambda$5(AuthLandingScreen.kt:184)
                                                                                                    	at creditgenie.presentation.signin_signup.ui.authlanding.AuthLandingScreenKt$AuthLandingScreenContent$5.$r8$lambda$IZzaE8SyegnLydx6ey2_lFOCPGg(Unknown Source:0)

The offending call is:

        analytics.track(
            name = eventName, // String
            properties = params // a MutableMap<String, Any?>
        )

Changing params to params.toMap() resolves the fix.

Expected behavior
A clear and concise description of what you expected to happen.
It doesn't appear that the latest release (1.24.1) has fixed the issue

Platform (please complete the following information):

• Library Version in use: 1.21.0
• Platform being tested: Android
• Integrations in use: N/A

[wenxi-zeng]

make sure the entries in your map is serializable.

[jrodbx]

Why would changing the MutableMap to a Map resolve this?

Changing params to params.toMap() resolves the fix.

The entries are identical - .toMap() creates a new Map with the same entries. The crash in ReflectionFactory.mutableCollectionType() happens during type introspection, not during serialization, so why would the mutability of the Map interface trigger a different reflection path that causes a ClassCastException?

[wenxi-zeng]

in this method, we only support Map. even though it looks like MutableMap use the same path as Map, but MutableMap carries different internal type metadata than Map. this is rather an implementation error in kotlin.jvm.internal.ReflectionFactory. as you can see in the source code of ReflectionFactory, mutableCollectionType is a completely different type. this also explains why your crash is from reflection instead of our library. I'd suggest you to upgrade your kotlin jvm library to latest, or write an serializer for mutable map your own.