Support, I am unable to activate any of the three upfront

Hello Support,

I am unable to activate any of the three upfront themes on this domain of mine http://wisespace.in

It hows that the installation is complete, but as soon as I click on activate theme, it gives me an internal server error.

After I remove the theme from the themes folder in the root directory, the website resolves fine.

What could be the problem? my server people were also weren't able to provide a reason or a fix to this.

I also haven't received any response on the ticket I opened yesterday, so thought of creating a new one.

Kindly look into it and reply at your earliest convenience.

Regards
Shrinivas