Magento2: Unable to create new category

[tahiryasin]

When I click Add Root Category or Add Subcategory button from Products > Categories page it doesn't load the form. Console shows below error message.

ReferenceError: updateContent is not defined

[guz-anton]

If after _Refresh_ page you still reproduce this then it kind of issue.
Then it would be handy to provide more details: do you change any default settings? How do you install Magento? What browser do you use?

[tahiryasin]

Yes, I refreshed page many times. I manually installed Magento by downloading from download page. No default settings were changed. And I was using Firefox V 42.0

[CalamityJames]

I am also getting this with a fresh install out of the box. No 404 errors appearing in the Network list so all files are being loaded.

I'm using Chrome 46.

If it helps it's this part:

            function addNew(url, isRoot) {
                if (isRoot) {
                    tree.currentNodeId = tree.root.id;
                }

                if (/store\/\d+/.test(url)) {
                    url = url.replace(/store\/\d+/, "store/" + tree.storeId);
                }
                else {
                    url += "store/" + tree.storeId + "/";
                }

                url += 'parent/' + tree.currentNodeId;
                updateContent(url);
            }

Edit: I notice comparing to a store with demo data installed that the form fields for adding categories is missing altogether on this install (see attachment):

[tahiryasin]

Issue resolved!
I am on Linux and issue was wrong CHMOD

below commands solved my problem.

find . -type f -exec chmod 644 {} \;
find . -type d -exec chmod 755 {} \;

[magebay99]

I got same problem but not solved by change permission. Is there other solution?
Magento 2.0.4

[magebay99]

---------------> solved after try again @tahiryasin solution. Thanks