SIM cards have nothing to do with it on WP, unlike Android. If you want the latest update, use the developer preview to check for an update. If there is nothing there, you are on the latest update for your phone.I think I can put Verizon sim card because Verizon already released gdr3 for their htc8x and download the update and switch back to tmobile. But only If I can I find someone with Verizon sim card
^it doesn't work that way. updates are not linked to sim cards they are linked to the carrier the phone is designated to.
is yours a T-Mobile HTC 8X? in other words, is there any T-Mobile markings on the device and did you buy it from T-Mobile?
SIM cards have nothing to do with it on WP, unlike Android. If you want the latest update, use the developer preview to check for an update. If there is nothing there, you are on the latest update for your phone.
Have you hard reset your phone? Other people have dev preview on their T Mobile 8x's
sim cards have nothing to do with it on wp, unlike android. If you want the latest update, use the developer preview to check for an update. If there is nothing there, you are on the latest update for your phone.
Edit: Didn't read the first post. It sounds like you are on gdr2, have you tried opting out of the developer preview, uninstalling the preview and then trying to manually update? If that doesn't work, have you tried to hard reset your phone yet?
What does that do ?
something is clearly wrong with your phone, given that other people on T Mobile have used the developer preview to update to GDR3. If you hard reset (make sure to backup your phone first), you can often fix problems such as this.
You need at least Amber firmware to get WP8.1
Where'd you find that? Because this is the first I'm hearing of it, and also irrelevant to the OP, seeing as he's using an HTC device.
That is GDR2, and Paul Thurrott said so.
It looks like you are still running GDR1, can you confirm the last time you updates the phone. What is the base and version number? It looks like HTC 8x on T-Mobile got the GDR2 update on September 4th to 8.0.10327.77. If you don't have it, you need to hard reset your phone and try to update it to GDR2, enroll in the Developer Preview, and then update to GDR3 and finally 8.1 when it comes out