Problems with events and Flutter SDK

sen_rce

Hi everyone
I have a situation with events + Flutter SDK versions and I’d really appreciate some help.

Context
At some point in the past we had events configured and working. Later (as far as I understand) our subscription expired, we didn’t upgrade the SDK to v4, and now the setup looks partially broken.

Currently:
 

• Some events work
• Some events don’t
• Most events have status unexpected

Question 1 — unexpected events & Flutter SDK as a source

Many of the unexpected events have Flutter SDK selected as a source.
But the behavior is very confusing:

In Sources, Flutter SDK looks connected
When I click it, I also see it as connected
 

• But I don’t see Flutter SDK in the list of available sources when configuring events
• At the same time, some events already have Flutter SDK selected as a source

Visually it looks like:

There is some “old” Flutter SDK
 

• And some “new” Flutter SDK
• When I select one of them, it looks different in UI (I’ll attach screenshots)

Question:
Is it possible that events are linked to an old Flutter SDK instance/version that no longer exists properly in Sources?
How can I clean this up or correctly re-link events so they stop being unexpected?



Question 2 — Users, SDK versions, and missing events

We also see strange behavior related to user IDs and SDK versions:

 

•  
  • Have short user IDs (1–4 characters)
  • Their events do not appear at all
•  
  • Have user IDs ≥ 5 characters
  • Their events appear normally
• There is at least one older user ID that is already on SDK 4.3.4, but:
  •  

We discovered that:

• In Flutter SDK v3, there was no minimum user ID length
• In Flutter SDK v4, the default minimum user ID length is 5 characters
• We currently do not override this setting

 

Questions:
 

1. Is there any way to force users on older SDK versions to “upgrade” so their events start coming through correctly?
2. Can SDK version differences alone cause events to be dropped or marked as unexpected?
3. Is there a recommended migration path when moving from SDK v3 → v4 to avoid losing historical users/events?

If needed, I can share:

• screenshots of Sources
• screenshots of events with unexpected status
• examples of user IDs + SDK versions

Thanks in advance  

Beth Saunders

Hey @sen_rce, I know you also asked this question in the Slack community but commenting here as well for visibility:

Events show as unexpected when they're new and haven't been added to the tracking plan. That's expected. Once you add them to your plan, they will no longer show as unexpected.

When you say "At some point in the past we had events configured and working. Later (as far as I understand) our subscription expired, we didn’t upgrade the SDK to v4, and now the setup looks partially broken." Have you still not upgraded the SDK version? That's probably part of your problem. It's always advised to update to the latest SDKs wherever possible. I would reach out to support to ask about old VS new Flutter events and the discrepancies you're seeing there.

I would assume that the lack of source data there is from old events or other implementation sources besides Flutter. Again, support can likely clarify this for you.

1. Is there any way to force users on older SDK versions to “upgrade” so their events start coming through correctly?
   • Unless you force people on an old app version to upgrade or make it un-usable, I don't think there's any way to "force" people to upgrade.
2. Can SDK version differences alone cause events to be dropped or marked as unexpected?
   • Events that are "unexpected" are new events in your taxonomy as mentioned above. Add these to your plan and they'll no longer show as unexpected.
   • In terms of dropped events, that sounds odd and I would ask support. It might be that specific events from the old SDK are no longer on the new one. But if it's an expected event that just randomly isn't being triggered for some users and not others, it sounds like a bug
3. Is there a recommended migration path when moving from SDK v3 → v4 to avoid losing historical users/events?
   • You won't lose historical users or events when you upgrade your SDK. All historical data in Amplitude persists. Correct me if I'm misunderstanding your question.