Some Google Messages users are reporting RCS activation failures after moving to newer Samsung Galaxy phones or switching carriers. Several complaints collected by 9to5Google involve the Galaxy Z Fold 8 and display error code 3100.
The reports have largely involved device migrations or carrier changes, although Google has not publicly confirmed the underlying cause or full scope of the problem.
In some cases, users moving from an older Galaxy phone to a new model said RCS stopped working after using Samsung’s Smart Switch transfer tool. Others encountered the problem after moving their phone number to another carrier. Google has acknowledged the issue and said it is working with carriers on a fix.
“We’re aware of this issue and are working with our carrier partners to get it fixed as soon as possible,” Google told 9to5Google.
The exact cause remains unclear. A Google support representative suggested that corrupted cache files transferred through Smart Switch could be involved in some device-switch cases, while carrier-switch cases may be tied to number-porting processes that have not fully completed.
That distinction matters because the same 3100 error can appear in situations with different underlying causes. A failed device migration and an incomplete carrier port may require different fixes.
Google’s recommended troubleshooting steps
Google recommends updating Google Messages, turning off RCS chats, clearing Carrier Services data, restarting the phone, and then turning RCS back on.
But those steps have not worked for everyone. Some users in online discussions said they resorted to factory resets or other workarounds, but Google has not endorsed those measures as reliable fixes. A factory reset can wipe a newly configured phone without guaranteeing that RCS connectivity will return. For users preparing to switch phones, some reports suggest disabling RCS on the old device before making the move and re-enabling it after the new phone is fully set up.
A bigger problem for Galaxy messaging
The timing makes the problem more noticeable for Samsung owners. Samsung has discontinued its Messages app in the U.S. and encouraged users to move to Google Messages, making Google’s app increasingly central to messaging on Galaxy phones.
That raises the cost of a relatively narrow software problem: when RCS fails, users can fall back to SMS or MMS, but they may lose features associated with RCS, including richer media messaging and read receipts.
The episode also exposes a weak point in the broader RCS transition. The service depends on multiple pieces working together — the messaging app, device software and cellular carrier infrastructure. A failure during something as routine as changing phones or networks can leave users stuck troubleshooting a problem they cannot easily identify.
Until Google and its carrier partners identify the cause, Galaxy owners changing phones or carriers should confirm that RCS has been disabled on the old device and successfully activated on the new one. They should also avoid factory-resetting either phone until calls, SMS, mobile data, and RCS are confirmed to be working.
Read more: Google Messages surpassed 10 billion downloads as Samsung’s shift toward the app made reliable RCS service increasingly important for Galaxy users.