Problems with SharePoint Syntex Content Assembly

[Bruno06600]

Hello,

I am trying to create a modern template (Syntex content assembly), and as soon as I load my template document, I have an error as shown in attached picture, (sorry we ran into a problem, with 2 options : restart or quit).

I've tried with differents browser such Chrome, Edge, Firefox, using a Windows 11 computer, up to date, and after 5 seconds, everytime I have an error. I am not able to use any text placeholder.

So, everytime my mouse's cursor moves outside Word document frame located on the left part of the screen studio, I see the error, I need to reload the Word document, and automatically, the template is published. And I can't delete the template. I saw that the template is in the -hidden form in the library.

Error via Console :

SyntaxError: Unexpected token H in JSON at position 0
at JSON.parse (<anonymous>)
at aB.ZF (WordEditorDS.box4.dll3.js:2635:503)
at h.W$c (WordEditorDS.core.js:2221:47)
at h.process (WordEditorDS.js:1109:338)
at I.Jta (WordEditorDS.box4.dll2.js:925:146)
at c.Jta (WordEditorDS.js:2261:94)
at y.qKf (WordEditorDS.js:1096:49)
at y.jic (WordEditorDS.js:1096:492)
at y.process (WordEditorDS.js:1094:388)

Do you know what can I do to create a modern template without running into issues ?

[#2]

Having the same problem and more. I do see the template engine crashing whenever the Word based template source has tables in it, even more if it has merged columns in that. But even in a 'clean' document the underlying contenttype is not created or not properly created, and modern template entries in the New menu just disappear when refreshing the page. I am a bit frustrated now, will contact support to find the root cause(s).