"End locked content call does not have a matching start locked content call" message

Anthony Rudd

Perhaps it's because the caret at the start of the opening tag means it can't find a match at all as you don't have any inline tags beginning at the start of the extracted structure, but it can find the closing tag.  Hard to know without seeing the content you are trying to tag.

The file content is correct

<artno>Article number

The tag pair "^<" ">" (without the quotes) has no problems with this file,
although it fails with the same message for <artno>Article <notag> number

But I now know what the message means. It seems that the tag processor makes some incorrect assumptions.

That's a placeholder, not a tag pair.

I had just come to the same conclusion, or more correctly, tag pairs have restrictions, only placeholders allow the required flexibility. 

Anthony Rudd said:

tag pairs have restrictions,

Yes, they need to be proper tag pairs!

This raises the question: what is a "proper tag pair"? I cannot find any definition.

Simple... and the same for pretty much any markup language:

<opening>maybe some stuff in here</closing>

Obviously not written ike that but hopefully you get the idea.  Also a google search gives me this pretty quickly:

https://docs.sdl.com/LiveContent/content/en-US/SDL%20Trados%20Studio%20Help-v4/GUID-C5CF90AD-83F2-4145-9173-1C6408A24509

Any other interpretation of what a tag pair could be is probably arguing for the sake of it... in my opinion!

Simple... and the same for pretty much any markup language:

<opening>maybe some stuff in here</closing>

Obviously not written ike that but hopefully you get the idea.  Also a google search gives me this pretty quickly:

https://docs.sdl.com/LiveContent/content/en-US/SDL%20Trados%20Studio%20Help-v4/GUID-C5CF90AD-83F2-4145-9173-1C6408A24509

Any other interpretation of what a tag pair could be is probably arguing for the sake of it... in my opinion!