I went to a page for a build I felt content with, and went through the process of logging in, attempting to save the build, attempting to search for builds, and closing the "Search Builds" popup, as the log does include the request for the darker close button image that appears when hovering over it. Here is a complete log of everything in the Firefox Developer Edition browser console. Note that the browser console formats things in a way I can't display in plaintext, nor can I display it in the extremely limited BBCode of these forums. I went ahead and made it human readable after copying it, but it's still a little bulky simply due to the uncompressed URL's. The browser console logs have left-aligned and right-aligned contents on each line, so this was really annoying to format without any macros.
Here is the log with the right-aligned contents all pushed to the same tab stop. You need to copy this into a proper fixed-width text editor with word-wrap turned off to view it properly. https://pastebin.com/GTW5pN3m
Here is the log with the right-aligned contents all preceded by 3 tabs. This is easier to read on the website, but not great for comparing lines. https://pastebin.com/QyG8XPs6
There's some weird things your website does that don't quite make sense to me.
I don't understand why you put the full details of the build into the URL, and offer use of a URL "shortener" redirect hosted by a third-party (a highly suspicious one at that), rather than compressing it. I can understand & relate to wanting to make the URL human-readable at a glance, but it's so cumbersomely long that it still currently fails in that respect.
It's alarming that you seem to have no security systems to speak of in place to protect user information & behavior from being tracked or stolen without their consent. I know HTTPS is very fiddly, but even just that helps. I really hope you only store hashed passwords server-side, use trustworthy RNG for key generation, and make sure keys are sufficiently long. Perfect forward secrecy is more involved, but kind of necessary to stop MitM attacks. Even without perfect forward secrecy, just making sure you don't reuse encryption keys is really good. I know ideal security is really annoying to get right, but even these relatively simple things would help.
The more attractive your website becomes, the more people are going to use your website. You may not ever see the day when someone has their credentials stolen, or their metadata leaked, but the chance of it happening gets slightly higher with each new unique visitor to the website. Currently, your website is the only remotely usable tool for quickly assembling and planning prospective builds in Warframe, and that advantage means everything you improve about it can create an influx of new visitors, which is amplified by how many existing users feel inclined to tell their friends about it.
Equipment is frequently added to the game, with equipment's stats changing from time to time. I think relying on end-users to report changes to the game is too slow to keep up with new content, especially as brand-new content is what everyone wants to try to build for. I know http://warframe.wikia.com (not encrypted, unfortunately) is usually up to date, and I know it has something that would be rather ideal to query automatically, but I don't quite know how you would go about doing that. I can barely navigate the place aside from the normal wiki pages, so all I could find was this: http://warframe.wikia.com/wiki/Special:Search?search=Module&fulltext=Search&ns828=1.
Line 8 looks cut off at the beginning. Thank goodness those scripts seem completely unrelated to this issue.