When we changed Sorties to Activities, one area we missed was browser cached filters on achievements. When you set a filter for your achievements, we store a small key in your browser cache to maintain the filter.
Unfortunately, when we changed the word "sortie" to "activity", we failed to warn you that you might need to clear your cache. The vast majority of your players will be unaffected by this issue, but your achievement reviewers might be. We're rolling out a small patch to address the issue. In addition to the patch, I strongly encourage you to clear your browser cache. Here's how you do it in Google Chrome.
Navigate to your Preferences
Open Advanced Preferences
Clear Browsing Data
Close and Restart Chrome
One you have cleared your cookies, quit Chrome and restart. You should now be able to go into Alludo without any issues.