Hello @nightsky30, please copy your system information from steam (Steam -> Help -> System Information) and put it in a gist, then include a link to the gist in this issue report.
Thank you @kisak-valve I've now added the system info.
I also want to mention that the pages are loading now, and it might have been fixed by a change between the June 12th Update and June 13th Update 1. I found this in the comments from another user regarding June 13th Update 1:

After June 13th Update 2 a few moments ago I was notified that I had an item in my inventory. I opened the green envelope menu and attempted to access my inventory to receive the following error:

Hello @nightsky30, are you still experiencing this issue on an up to date system?
Yes, this appears fixed. Thanks
Nothing extracted yet.
Your system information
Please describe your issue in as much detail as possible:
After the latest beta update, pages are loading very very slowly or not at all.
Steps for reproducing this issue: