EMM cause (LTE NAS)3GPP TS 24.301 §9.9.3.9 and Annex A
What it means
MSC temporarily not reachable: the combined attach worked for LTE but the SGs/CS part failed for now.
Where you see it
In LTE NAS Attach reject, Tracking area update reject, Service reject or Detach request.
What to check
Check the SGs association between MME and MSC/VLR.
Look at the S6a (MME↔HSS) and S11 messages just before the reject: they usually show the real trigger.
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