“Page Not Found” on Create Chart

I’ve seen a lot of people report this issue, but no answers on how to resolve it. I’m trying to create an extremely simple chart (it only has 9 data points). It uploads the data just fine, and I can make customizations, but any time I try to save it, it just takes me to a “Page Not Found” page. I’ve tried deleting the plug-in and reinstalling it. I’ve tried deactivating all other plug-ins. It still doesn’t work. It does have a small warning at the top of the normal page that says, “allow_url_fopen option is disabled in your php.ini config. Please, enable it by change its value to 1. This option increases the speed of remote CSV uploading.” I don’t think I have access to that file, and I don’t think it would cause this issue. The CSV uploads just fine.

Any idea how to fix it? I’m about ready to give up and just upload an image of the graph.