I've gotten "Assertion Failed" errors before but not a huge wall of text like this one before:
release-453 (x64)
Uncaught Error: Assertion Failed: Attributes must be numbers, strings or booleans, not {currentSrc: http://radiant/stonehearth/entities/furniture/not_much_of_a_bed/not_much_of_a_bed.png, sizes: , y: 206, x: 493, width: 200, vspace: 0, useMap: , srcset: , src: http://radiant/stonehearth/entities/furniture/not_much_of_a_bed/not_much_of_a_bed.png, naturalWidth: 300, naturalHeight: 300, name: , lowsrc: , longDesc: , isMap: false, hspace: 0, height: 200, crossOrigin: null, complete: true, border: , alt: , align: , onwaiting: null, onvolumechange: null, ontoggle: null, ontimeupdate: null, onsuspend: null, onsubmit: null, onstalled: null, onshow: null, onselect: null, onseeking: null, onseeked: null, onscroll: null, onresize: null, onreset: null, onratechange: null, onprogress: null, onplaying: null, onplay: null, onpause: null, onmousewheel: null, onmouseup: null, onmouseover: null, onmouseout: null, onmousemove: null, onmouseleave: null, onmouseenter: null, onmousedown: null, onloadstart: null, onloadedmetadata: null, onloadeddata: null, onload: null, onkeyup: null, onkeypress: null, onkeydown: null, oninvalid: null, oninput: null, onfocus: null, onerror: null, onended: null, onemptied: null, ondurationchange: null, ondrop: null, ondragstart: null, ondragover: null, ondragleave: null, ondragenter: null, ondragend: null, ondrag: null, ondblclick: null, oncuechange: null, oncontextmenu: null, onclose: null, onclick: null, onchange: null, oncanplaythrough: null, oncanplay: null, oncancel: null, onblur: null, onabort: null, spellcheck: true, isContentEditable: false, contentEditable: inherit, outerText: , innerText: , accessKey: , hidden: false, webkitdropzone: , draggable: true, tabIndex: -1, dir: , translate: true, lang: , title: , childElementCount: 0, lastElementChild: null, firstElementChild: null, children: [object HTMLCollection], onwebkitfullscreenerror: null, onwebkitfullscreenchange: null, nextElementSibling: null, previousElementSibling: null, onwheel: null, onselectstart: null, onsearch: null, onpaste: null, oncut: null, oncopy: null, onbeforepaste: null, onbeforecut: null, onbeforecopy: null, shadowRoot: null, dataset: [object DOMStringMap], classList: , className: , outerHTML: 
, innerHTML: , scrollHeight: 200, scrollWidth: 200, scrollTop: 0, scrollLeft: 0, clientHeight: 200, clientWidth: 200, clientTop: 0, clientLeft: 0, offsetParent: [object HTMLDivElement], offsetHeight: 200, offsetWidth: 200, offsetTop: 0, offsetLeft: 105, localName: img, prefix: null, namespaceURI: http://www.w3.org/1999/xhtml, id: portrait, style: [object CSSStyleDeclaration], attributes: [object NamedNodeMap], tagName: IMG, parentElement: [object HTMLDivElement], textContent: , baseURI: http://radiant/stonehearth/ui/root/index.html?current_screen=title_screen, ownerDocument: [object HTMLDocument], nextSibling: [object Text], previousSibling: [object Text], lastChild: null, firstChild: null, childNodes: [object NodeList], parentNode: [object HTMLDivElement], nodeType: 1, nodeValue: null, nodeName: IMG}
Error: Assertion Failed: Attributes must be numbers, strings or booleans, not {currentSrc: http://radiant/stonehearth/entities/furniture/not_much_of_a_bed/not_much_of_a_bed.png, sizes: , y: 206, x: 493, width: 200, vspace: 0, useMap: , srcset: , src: http://radiant/stonehearth/entities/furniture/not_much_of_a_bed/not_much_of_a_bed.png, naturalWidth: 300, naturalHeight: 300, name: , lowsrc: , longDesc: , isMap: false, hspace: 0, height: 200, crossOrigin: null, complete: true, border: , alt: , align: , onwaiting: null, onvolumechange: null, ontoggle: null, ontimeupdate: null, onsuspend: null, onsubmit: null, onstalled: null, onshow: null, onselect: null, onseeking: null, onseeked: null, onscroll: null, onresize: null, onreset: null, onratechange: null, onprogress: null, onplaying: null, onplay: null, onpause: null, onmousewheel: null, onmouseup: null, onmouseover: null, onmouseout: null, onmousemove: null, onmouseleave: null, onmouseenter: null, onmousedown: null, onloadstart: null, onloadedmetadata: null, onloadeddata: null, onload: null, onkeyup: null, onkeypress: null, onkeydown: null, oninvalid: null, oninput: null, onfocus: null, onerror: null, onended: null, onemptied: null, ondurationchange: null, ondrop: null, ondragstart: null, ondragover: null, ondragleave: null, ondragenter: null, ondragend: null, ondrag: null, ondblclick: null, oncuechange: null, oncontextmenu: null, onclose: null, onclick: null, onchange: null, oncanplaythrough: null, oncanplay: null, oncancel: null, onblur: null, onabort: null, spellcheck: true, isContentEditable: false, contentEditable: inherit, outerText: , innerText: , accessKey: , hidden: false, webkitdropzone: , draggable: true, tabIndex: -1, dir: , translate: true, lang: , title: , childElementCount: 0, lastElementChild: null, firstElementChild: null, children: [object HTMLCollection], onwebkitfullscreenerror: null, onwebkitfullscreenchange: null, nextElementSibling: null, previousElementSibling: null, onwheel: null, onselectstart: null, onsearch: null, onpaste: null, oncut: null, oncopy: null, onbeforepaste: null, onbeforecut: null, onbeforecopy: null, shadowRoot: null, dataset: [object DOMStringMap], classList: , className: , outerHTML: , innerHTML: , scrollHeight: 200, scrollWidth: 200, scrollTop: 0, scrollLeft: 0, clientHeight: 200, clientWidth: 200, clientTop: 0, clientLeft: 0, offsetParent: [object HTMLDivElement], offsetHeight: 200, offsetWidth: 200, offsetTop: 0, offsetLeft: 105, localName: img, prefix: null, namespaceURI: http://www.w3.org/1999/xhtml, id: portrait, style: [object CSSStyleDeclaration], attributes: [object NamedNodeMap], tagName: IMG, parentElement: [object HTMLDivElement], textContent: , baseURI: http://radiant/stonehearth/ui/root/index.html?current_screen=title_screen, ownerDocument: [object HTMLDocument], nextSibling: [object Text], previousSibling: [object Text], lastChild: null, firstChild: null, childNodes: [object NodeList], parentNode: [object HTMLDivElement], nodeType: 1, nodeValue: null, nodeName: IMG}
at new Error (native)
at Error.EmberError (http://radiant/stonehearth/ui/root/js/libs/ember-1.8.1.js:14251:23)
at Object.Ember.assert (http://radiant/stonehearth/ui/root/js/libs/ember-1.8.1.js:3865:15)
at http://radiant/stonehearth/ui/root/js/libs/ember-1.8.1.js:8147:15
at Array.forEach (native)
at bindAttrHelper (http://radiant/stonehearth/ui/root/js/libs/ember-1.8.1.js:8136:15)
at program1 (eval at (http://radiant/stonehearth/ui/root/js/libs/handlebars-v1.3.0.js:1:0), :28:110)
at prog (http://radiant/stonehearth/ui/root/js/libs/handlebars-v1.3.0.js:457:17)
at CoreView.extend.render (http://radiant/stonehearth/ui/root/js/libs/ember-1.8.1.js:42299:20)
at EmberRenderer_createElement as createElement
I had the speed of the game on fast forward and received a traveling merchant message requesting 8 mean beds, switched over to carpenter GUI, selected 10 mean beds to make and po0f this error popped up, big ole wall o' words.
Just thought I'd post it since I've never seen this one before.