Bug in ace-editor is present since that we updated in 1.3.1. Because diff between 1.3.2 and 1.3.1 is big (-1288 +4661) with new feature... We prefer just patch the library in stable branch applying part of commit: https://github.com/ajaxorg/ace/commit/1890598a5da2259cfb0ceac38fed7bca582765db To do in master? : upgrade ace.js How to reproduce: > create ir.ui.view > be sure to empty all the content > type '<xpath expr=""' > Now if you type the > it will crash - Cannot read property 'type' of null closes odoo/odoo#43955 X-original-commit: 1a90740b8e699fc3afa28c3ddb5490328facb995 Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>