Changed theme to fashionistas, Adsense refused to work

SO I’ve upgraded my WordPress site with a new theme. The theme is called fashionistas. I doubt that the theme causes the problem. It may be the changes I made while migrating to a new theme that causes the issue. Here’s what I received from a message when placing ads on my site:

Sorry we were unable to save your configuration. The request to your server returned an unexpected result. This may be due to an incompatible theme or plugin.

I’ve read several forums before and found only 2 helpful similar problems. What they recommend was; using purge cache, disable all plugins except Adsense, revert back to the old theme, and then change to another browser, in this case, a solution provider find out the best browser to use is safari.

My dilemma:
1- I have no idea how to purge cache
2- Do I have to do all the work above?
3- I am using windows right now, not sure whether I can use safari.

Does anyone have problems like this before?

Thanks in advance ??