HTML 5 Firefox Error what does this mean?

I need to get my project into HTML 5 TODAY every time i do it i get a Firefox error that says

Error: uncaught exception: abort() at jsStackTrace@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:1:18192
stackTrace@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:1:18375
abort@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:174:78449
iDR@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:165:91893
Ooz@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:105:802135
bpz@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:105:804309
oEM@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:65:532480
lEM@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:65:525441
dEM@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:65:522368
qwM@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:65:163880
hdc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:342233
mdc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:345543
Wcc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:338117
zdc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:349620
Bdc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:351637
PYd@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:69:799824
q_d@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:69:854392
p_d@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:69:851698
v_d@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:69:858389
t_d@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:69:857111
K_d@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:69:863772
J_d@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:69:863605
Mwf@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:53:982029
$wf@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:53:985678
ync@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:608293
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607853
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607982
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607982
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607982
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607982
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607982
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607982
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607982
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607982
wnc@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:607982
_fd@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:1130822
Yfd@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:1129733
Wfd@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:1124919
Vfd@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:1124279
cgd@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:37:1133787
Cq@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:85:43104
Pq@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:85:46629
oyR@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:165:71527
Runtime.dynCall@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:1:4377
Browser_mainLoop_runner/<@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:1:237804
Browser.mainLoop.runIter@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:1:162140
Browser_mainLoop_runner@file:///C:/Users/Marquis/Desktop/HTML%20MORELIA/HTML5/UE4Game-HTML5-Shipping.js:1:237700

If this abort() is unexpected, build with -s ASSERTIONS=1 which can give more information.

Yes it happened immediately

It could mean a lot of things, jsStackTrace normally means that an exception within a js file that was called from native was raised. Do you know the time when it happens? At startup?

Okay how do I add more “assertions”

From a source build you will be able to build with more output as the last line of the error suggests.

You would need to add the line Result += " -s ASSERTIONS=1"; in the HTML5ToolChain.cs e.g. in the GetSharedArguments_Global function at Engine\Source\Programs\UnrealBuilTool\HTML5.

Does this error occur when you run your game locally or from a web host? Maybe this question and answer could solve your problem.