Whenever a user tries to edit the Space Permission and update its information, Confluence fails to do so and report the following error:

[Error] Error: Syntax error, unrecognized expression: [name=confluence_initial_viewspace_group_<instance_group>]

It happens if the space has given a permission to a group which has a white space in the group name (i.e test group).

Steps to reproduce

1. Create a Space and create a group with a similar name.
   For example:
   • Space: Space test
   • Group: Space test

1. Try to update the Space Permission by adding the Space test group.
2. Hit Save All.

Expected behaviour

1. The permissions should be updated.

Actual
Nothing happens and all buttons are greyed out.
The following error appears on the console:

[Error] Error: Syntax error, unrecognized expression: [name=confluence_initial_viewspace_group_<instance_group>]

Additional info
Confirmed this will only affect Webkit based browsers, like Google Chrome and Safari.

Workaround
Use other browsers, like Mozilla Firefox or Internet Explorer.