Thanks for the response. Please see my comments below.
> The problem is not just the 404 problem you’re referring to. Your plugin use a very custom ajax-based interface to edit products. It is impossible for a plugin to add multilanguage functionalities without doing specific code.
All of the products data in Ecwid is stored in the cloud, so there is no store posts or pages in WordPress your plugin could “multilang”. We understand that —
Ecwid is by design a SaaS solution, so an extra functionality would need to be added to your plugin to work with the Ecwid APIs. That would be cool, of course, if you can do that (we can provide the APIs to you), but again — within the scope of this issue, this is OK that the product/categories are not translated here.
So, the main issue we see here is those 404 errors because they make the site not usable and we want to fix that.
> The 404 happens because the rewrite rules are regenerated on every page and overwrite extra rules added by Sublanguage for handling translations (I think they should only be regenerated on admin side, for performance reason).
Can you elaborate on this a bit? Does Ecwid plugin (when enabled) prevents yours from creating the necessary rewrite rules?