Profile: Support

You are right.
Read this topic
[url=You are right. Read this topic https://community.moneris.com/product-forums/f/5/t/280 I'll do the new release]https://community.moneris.com/product-forums/f/5/t/280[/url]
I did the new release

>We just need to export one product and include comma separated attribute values, but only those that are in stock.

You don't want to export product attribute combination as new item.
You want to export the one product with the list of in stock possible attributes values.
The plugin has the token - 'All product attribute values "XXX"' (in stock and out of stock).
But you need to export only in stock possible attributes values.
You need to create the plugin for Feed Manager
https://www.foxnetsoft.com/documentation-nopfeedmanager#q14

and filter all product attributes and create the custom values with the list instock attributes.
If you don't have a developer you need to write to me 'support@foxnetsoft.com'.
It will be a custom work.

1. Open the feed template and select the third tab. Enable "Export product attribute combination".
2. Add the token for field Size(Color) - product attribute 'Size(Color)'
3. Add the restriction - quantity>0

Create the feed file.

It was a bug. I have fixed it. Thank you.

It was a bug, I have solved it in the last release. Thank you.

<ExportFileType>JSON</ExportFileType>

The plugin doesn't create json file.

Nop team did a SQL script for upgrade nop 4.20 to nop 4.30.
You need to execute this script.

Execute this command

INSERT [MigrationVersionInfo] ([Version], [AppliedOn], [Description]) VALUES (637160666562551771, CAST(N'2020-03-18T07:23:31.000' AS DateTime), N'Nop.Data base schema')

Did you install the fresh nop 4.30 or upgrade the old nop instance?

Can you check if Migration table has the value?
Execute this command

select * from MigrationVersionInfo where [Description]='Nop.Data base schema'

Check the first string on this error message. You will see the name of the plugin with  the issue.
Nopcommerce 4.30 uses FluentMigrations and tries to install the plugin, but the old plugin doesn't have information about FluentMigrations.

What nopcommerce version do you use?
Nop 4.30?