RWS Trados SR1: Preview based on self build xslt file does no longer work

Question

We have been using a self build xslt stylesheet to preview custom filter based XML translation projects. The preview worked for SDLTrados 2019 and RWSTrados 2022 until we upgraded to SR1. Now we get a blank panel in Preview. 
 - tried uninstalling, re-installing but the Preview stays blank in the Preview panel in the translation editor. 
 Q: are there new requirements for xslt stylesheet based previews? 
 here the 2 relevant screen shots.

and this one

Paul · Answer

Michael Metzger Can you try making sure that you have this before the body element of your stylesheet? For example: A change was implemented from 2021 onwards that requires the addition of the header element to your xslt. I don't know why yet, as adding an empty element pair like this seems a little pointless, but I will update when I get more information. Let me know if this is the problem you are having with your stylesheet?

Paul · Answer

Michael Metzger 
 We now have a KB article for this: 
 https://gateway.sdl.com/apex/communityknowledge?articleName=000019668 
 It seems Studio adds metadata to the html that is created to display the preview. It looks for the head element to add the metadata to it and if it's not there it throws the error. Not too clever but at least we know why and it's simple to avoid.

Paul · Answer

Michael Metzger Can you try adding as an empty tag pair instead?

Paul · Answer

Thanks Agija Kemmann 
 I can only confirm that I can repro the problem in 2022 SR1 CU7. I can also validate it working correctly in 2021. 
 I have logged it for checking and resolution. Once I have more details I'll let you know.

Paul · Answer

Agija Kemmann 
 Thanks for sending in the settings file. The tech support team looked at this yesterday and identified that you built your custom filetype using the old XML filetype and this is no longer supported in 2022.They recreated it in 2022 using the new filetype, added your stylesheet and all is well. 
 I'll send you the updated settings file shortly.

Trados Studio > 1. Trados Studio

RWS Trados SR1: Preview based on self build xslt file does no longer work