Error while rendering template [htmlheader.vm] when clicking on 'Forgot your username' and 'Forgot your password' making the templates unreachable

Steps to reproduce

1. Click on Drawer > 'Log-in'
2. Click on 'Forgot your username'
3. Go again on Drawer > 'Log-in'
4. Click on 'Forgot your password'

Expected results

The users is directed to respective templates:<server>/xwiki/authenticate/wiki/xwiki/retrieveusername and repective, <server>/xwiki/authenticate/wiki/xwiki/resetpassword where the forms for filling the username/ email address are present.

Actual results

When clicking on each of two links, there are some errors displayed on browser (the UI is broken) and on XWiki console and the templates are unreacheable.

When clicking on 'Forgot your username':

Error from browser: https://up1.xwikisas.com/#mNbW7xog-xJKOcQWM6UbWg

Error from XWiki console: https://up1.xwikisas.com/#OpIgq7VahYF6tksispTG0A

When clicking on 'Forgot your password':

Error from browser: https://up1.xwikisas.com/#qEqMwyqjGANaPDOVO09vpA

Error from console: https://up1.xwikisas.com/#FjlfPqwNqdc4iApG09NclA

The issue could not be reproduced on XWiki 16.4.4, 15.10.13 or 16.8.0.