Microsoft says that they are not going to fix Error 80188306.

[Vicky Krishnatrai]

Yesterday, I got an email from Microsoft and that was about error 80188306 for PfD WP 8.1 update 1. It looks like that they are not going to fix mention error. Here is the copy of email.
Hello,

We have investigated this error further and have determined that it is caused by the version of Windows Phone installed on the device not matching what the new update was expecting. To resolve this, you will need to contact your mobile operator or Nokia to reinstall Windows Phone 8.1 with the proper version.

Please reply to this email with any additional questions you may have. We will check in with you in a few days from now to see how you are progressing if we have not heard from you by then.

Regards,
Aaron B.
Microsoft Support

 

[dKp1977]

Kinda weird, but I assume it's just too expensive to get their devs fixiing it, regarding only very few users are affected by it. Not to mention of course, that you always use beta software at your own risk.
I suggest you use the Nokia Recovery Tool to perform a rollback to 8.0 and start back from there (if you want to of course). I did that with my 1020, which had gotten very very slow after all those beta updates. Now it's performing perfectly fine again.