Theme conflicts with c5.6.3.4.

I bought a theme, and the developer has stopped offering support. I updated to c5.6.3.4 and now there's some problems. First of all I continually get logged out. When I sign in the home page is in edit mode but as soon as I navigate to any other page I am logged out again. Sometimes I can go to dashboard and navigate from the sitemap to other pages to edit, but sometimes I get logged out when I try to access the dashboard. I then cannot log in anymore.

Then there are error messages when I edit blocks. I can't close the edit window. I have to reload page, then the edits are all saved.

Also people are reporting errors when trying to submit a form. I cannot replicate these errors but it seems the get a No permission to access the page error.

I went into browser debug console to check for js errors.
These are some of the errors shown, can anyone help to resolve?

Use of getPreventDefault() is deprecated. Use defaultPrevented instead. jquery.js:3:7108

Use of getPreventDefault() is deprecated. Use defaultPrevented instead.

The character encoding of a framed document was not declared. The document may appear different if viewed without the document framing it. index.php

Use of getAttributeNode() is deprecated. Use getAttribute() instead.

Handler function NRL_getSecurityInfo threw an exception: TypeError: this.transport is null
Stack: [email protected]://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/main.js:1347:5
[email protected]://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/webconsole.js:2029:5
[email protected]://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/webconsole/network-monitor.js:263:5
makeInfallible/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/DevToolsUtils.js:87:14
[email protected]://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/webconsole/network-monitor.js:217:5
Line: 1347, column: 5 DevToolsUtils.js:63:0

TypeError: this.transport is null main.js:1347:5

View Replies:
Steevb replied on at Permalink Reply
Which theme?
rritz replied on at Permalink Reply
Theme is Treviso by c5 mix
AndyJ replied on at Permalink Reply
Have you cleared your cache and are you able to purge mod_pagespeed?
rritz replied on at Permalink Reply
I have cleared the cache, but this didn't help.

I don't understand the part about purge mod_pagespeed, if you can explain I can try
rritz replied on at Permalink Reply
I found an old thread where people were having the same problem

Someone said:

The json-line is returned by the process storing a new or updated block. As blocks are stored with an ajax call it just prints a json object as return for the ajax call (find it in /concrete/startup/process.php line 804 for version
Now if the json object is displayed in the browser window rather than processed by a javascript call, this implies that the block's add/update form was submitted without using ajax. And this implies that javascript crashed somewhere before.

At least in my case this was the problem. There was an error in the auto.js file of my blocktype, and since auto.js is loaded dynamically no message was displayed in the console. "