Yes… if the conversion script is not writing the tag name correctly as the tag is part of the schema and has to match exactly.
Not sure why only the pm_system is using the underscore while all the other tags use the dash? Another one of those Seamly mysteries. 
Personally I would have preferred all tag names and attributes in camelCase with no underscore OR dash as it is in Seamly2D.
@Pneumarian This is great! Thank you! It works now. And just to make it clear to anyone who might run into this same issue; all the required, minimum changes to the file were:
<Version>0.3.3</Version> to <version>0.3.4</version>
Also, <pm-system>998</pm-system> to <pm_system>998</pm_system>
Thanks @samitapani… I’ll make sure to bring it up at next week’s meeting that the script needs to be updated.