Yes, there seems to be a problem with the default sticker set in Viber 5.2. Lot of users have reported the problem.
There is still no official explanation to what is going on. We hope it will come back soon.
What is the Sticker market?
If you want to use a sticker to make a visual statement or just to spice up your conversation, you can go to the Sticker market and choose a sticker. The Sticker Market has more than 1000 stickers; a lot of them are free to download and use, but there are some which you have to pay for. You can find the Sticker Market in the “More Options” menu of the Viber application or through the ‘+‘ icon in the sticker menu.
Currently, the Sticker Market is available as an in-app feature that is supported on Android and iPhone devices only. There is no access to the Sticker Market through Viber for desktop.
It’s also good to know that, from time to time , Viber hires freelance designers to create Sticker Packages. If you have designed Stickers for Viber, make sure to send your contact information and portofolio to firstname.lastname@example.org.
Getting a sticker from Sticker market
After entering the Sticker market, you just need to choose the sticker package you want: if you choose a free package, it will be automatically download to your device and be ready to use. Paid sticker packages will be downloaded after the app guides you through the payment process.
After payment, just like free stickers, the stickers will be downloaded and available for use. You can find them in your sticker menu: look for the icon with a green star indicating a new sticker package.
Once downloaded, stickers are yours to keep and they won’t expire. And yes, they will sync to your secondary device(s). If you find that stickers are not synced for some reason, just use the Refresh icon in the stickers menu and they will show up.
Deleting stickers from Viber
Stickers can be fun to use but there is a catch: once downloaded, stickers cannot be removed from Viber. That can be annoying for some users and, at this time, the only solution for removing stickers is to uninstall Viber and install it again. Viber Media Inc. is aware that removing stickers is a missing feature and they are planning to make this available in future versions.