Internal Server Error on Processing orders

Hello,
I have a pretty urgent question,
I could narrow it down already a bit.
Last week i installed the multi-currency plugin, and since, there where 2 orders made in GBP. Since then i cannot load my processing orders in the admin anymore. I copied my site to a tempsite, and changed status to completed of the 2 orders in GBP, and now the completed tab is not loading anymore, but the processing is again..

So there is something going wrong. Disabling the plugin doesn’t help, so it must be due to something written differently in the database where he is crashing on. I’m all up to date with woocommerce/wordpress/plugins.

The page I need help with: [log in to see the link]