this bug was introduce by the inline z-index define inside the template 'web_editor.FieldTextHtml.fullscreen' (https://github.com/odoo/odoo/commit/912996fe902c41cafa12dcfe09713ce9857f95ab#diff-76a385e3a3e67f1b88b34afd8181f732R13) This was breaking the z-index web-editor dialog (using inside mass-mailing), so a first fix using a new z-index was made for the web-editor dialog (https://github.com/odoo/odoo/commit/65c8d33c2922bd90e2755cff0a6751c8b3b130d8) But we a missing a scope to identifiable a web-editor dialog was missing. So this commit add a class to allow target only the web_editor dialog. Task ID: 2198649 closes odoo/odoo#45702 X-original-commit: 441a5fa5a67f25398744ea18860eebdc4d17dddb Signed-off-by: Pierre Paridans <pparidans@users.noreply.github.com>