Blank captcha problem in Kolotibablo

Today we all are getting problems of blank captchas in Kolotibablo. It looks like this:

Blank captcha appears and we don't know what to type. 

So what do we type here? Any solutions? If we type random words we are getting low accuracy and will be banned.

If anyone has same problem and solution for it, please let me know because main admin is not responding.

Hope we all can solve this problem.