I used an online translator service, so I hope I got this right. Please check if logging out and back into your account fixes the issue. In the admin backend, your account does not show anything unusual, so it might be an issue with cached game files locally.
Could you please let us know what platform/OS/browser version you are playing on and where exactly the purchase process fails? The shop looks just fine on our test devices and backend, so any additional info will help to find the issue you're experiencing.
I have been kicked 3 times just this morning and that was AFTER I deleted the app and re-loaded it. I don’t even get an “offline” message most times - there’s just no activity (after several quick turns) and when I refresh, I find out I’ve been kicked. This is absolutely ridiculous.