Server Code: 200

Hello
Sorry for my English I am French.
First, congratulations for your plugin. This is for me the best and very useful.
I use it often but I encounter a problem when restoring a site. Indeed from step 1 I immediately got the error message:
Server Code: 200
Status: parsererror

I tried manually as described here https://www.ads-software.com/support/topic/server-code-200-status-ok/
but without success