1st, I'm using Fx 52.8.0 ESR in Linux. I've created custom search engine plugins before, but http://mycroftproject.com/submitos.html - with a template to create a plugin & "test it" has changed some terms, requirements on their site (it seems). In fact, the plugin - used from Fx search bar, brings an empty DDG page (even allowing scripts, cookies). Something the Mycroftproject template accepted is obviously not right. I created one for DuckDuckGo using 8 or 10 custom parameters from DDG's "customize settings" page. Mycroft Project has lots of custom DDG plugins already posted, but I'd like to learn how to do it quickly for numerous sites. I used "show full instructions." Under Search URL, I entered the domain & the custom parameters: https://duckduckgo.com/?kn=1 [example is shortened]. Other than using a script - I stored somewhere - to open the archive, ~/.mozilla/firefox/{profile name}/search.json.mozlz4, I don't see a way to check if a search plugin is using the correct parameters. Plugin created on MycroftProject isn't working: If I do a DDG search from the search bar, the results page is blank (not even an empty search box). Can someone post a link to a complete example for DDG, that uses complete sentences & actual values, unless DDG or the Mycroft plugin creator wants symbolic entries like "{searchTerms}?" If I open a DDG page using the bookmark w/ parameters - that DDG created, then a search from their search box works. It's apparently not what OpenSearch wants. Either way, opening a DDG page with their bookmark, if I click their settings link, that page opens showing all <strong>default parameters,</strong> not my custom ones that are showing in the URL bar. ** Isn't there an easier way to see the parameters used - especially if the plugin DOES work? Another issue: When creating the plugin, http://mycroftproject.com/submitos.html showed an error: "No {searchTerms} parameter found. (case sensitive)" Where (all) are they expecting that? After all custom parameters? Are they wanting the actual symbolic {searchTerms} - entered where? Read several sites about using the Mycroft template - I decided to enter "{searchTerms}" under "Post Parameters." It shut up, but the plugin didn't work. Note: One DDG, parameters like kn=1, are the same for Get or Post method, except the parameter instructing to use Get or Post. I'm not sure what they want under Post Parameters. DDG supports Post. Image not used: Mycroft plugin creator asked for an image or icon. Mentioned 16x16 - maybe for an icon, but I uploaded a 16x16 png. When plugin is created, it uses Mycroft's site icon, not the DDG I uploaded. Maybe it wants images w/o square backgrounds?