It was r60. I just installed latest version overwriting old files to make sure that there is no modification on script which obviously broke my customized theme. Anyhow I switched to Default theme and tried to Claim reward and got same error but now "line 2061".
Well... I have to say that I have no idea why that's happening. Here's what you can check, but it might just be easier/faster to change hosting:
1. Do you see any "REFERER CHECK FAILED, ASSUMING CSRF!" errors in your server's error log?
2. Does it help if you temporarily remove line 90:
$_POST[$_SESSION['address_input_name']] = "";
from index.php?
3. can you put
trigger_error("Address input name changed");
in line 2388, like that:
Line 2387: $data['page'] = $page;
Line 2388: trigger_error("Address input name changed");
Line 2389: $_SESSION['address_input_name'] = randHash(rand(25,35));
and then visit your page once and see if this error was added only once to your server's error log? (it's important to check the error log and not only in browser)