Achievements disappeared.

Last Night I noticed my gamerscore dropped from about 168,550 to 142,895. For some reason, about 50% of my Xbox One games are showing as 0/1000 despite having multiple achievements in them all. It seems to have only affected Xbox One games. Luckily I managed
to screenshot my account on TrueAchievements before it managed to drop as seen here: Imgur. I contacted support and followed the steps and they told me to post here. Any help would be massively appreciated.

:)

 

Xbox One achievement error. Code 0x87c40011

I get a message like "your achievements have not disappeared but we can show them for now".

Yes, they have not disappeared but i miss G score ...

 

Achievement disappeared

I recently bought the new console and had transferred all my old data to new hard drive. I played Borderlands for last two achievements (The Angelic ruins & Big Tournament) which I got and they popped up on screen, but
was told it wasn't showing by friends on list, yet I could see them on my achievement list. I decided to download my profile again and the achievements disappeared on me. I really don't want to have to replay all over again. Can someone please explain why
this has happened?

 

Sorry to hear it. This may be due to a gamerscore reset. Please log in to http://enforcement.xbox.com/ and click the hammer icon to check it out. If this is the case you won't be able to re-earn any achievements
for those games on your account again.

 

I've just checked and nothing appears there other than an old communications ban.

 

Well it seems to have fixed itself! Thankfully