FAQ on the Magento 2 Plugin

PHP Warning: Input variables exceeded 1000. To increase the limit change max_input_vars in php.ini.

For orders that contain too many products, this PHP warning may be issued. You will have to edit your php.ini file and restart your server.

The variable that you must change is called max_input_vars. This is the maximum number of variables that can be sent in a request. You can change it, for example, to 3000. The default is 1000.

Parameters: description/unitPrice/quantity are required for each orderline, but was not set for line: xxxx

The same problem as above. The request is being truncated because the number of variables are exceeding the max_input_vars limit.