Error Code 90001214
This error code is usually occurs when you send conflicting values to Amazon.
For example, the manufacturer_minimum_age value cannot be less than the manufacturer_maximum_age value or it must be at least equal to manufacturer_maximum_age value, as shown in the error image below.
Let's look at the source of this error.
As seen in the pictures shared below, the value "18" for the mfg_minimum field, "Years" for the mfg_minimum_meausure_of_unit field, "5" for mfg_maximum, and "Years" for mfg_maximum_unit_of_meausure were sent to Amazon. In this case, because the mfg_minimum_unit_of_meausure value is entered incorrectly, Amazon thinks that mfg_minimum is higher than mfg_maximum and gives an error.
In order to correct the error and publish the listing properly, one of the valid values for the mfg_minimum_meausure_of_unit field, "Months", must be entered. As a result, the error will disappear since "18 Months" is less than "5 Years".
Note: When you encounter this error code, the case may not be the same as above. However, what you need to look for in your database is that there are conflicting values as described above.