What price is your plan set to? It's expecting an actual decimal value and looks like an invalid value format is trying to be stored in that column.

Have added a bug ticket for further investigation. Looks like the mapping of the basket data to IPN data isn't mapping payment_fee correctly.

forge.joomlapolis.com/issues/8699

There are 2 separate issues reported here that I have tried to reproduce and analyzed:

1. "Incorrect decimal value for column ‘*******_jooml7*’.’josgt_cbsubs_notifications’.’payment_fee’ at row 1"

I could not reproduce it, as Paypal Sandbox sends a correct value in payment_fee field here, but it would be useful to have the corresponding Paypal Sandbox notification record containing among other theings (typically in $_POST) corresponding notification or, if the notification wasn't recorded the corresponding error log.

So if we could see the notification it would help to make sure we fix any other possible issues of such invalid or incomplete Paypal notifications (for payment_fee, it's already fixed in my copy, to be released in a nightly once we see if there are other potential issues).

2. For the 2nd try that gave "Things aren’t working as they should, try again.": That error message from Paypal is not very helpful. Usually that means that a parameter is not what Paypal expected and trying later won't be help. But there is help hidden:

To find the issue, look at network accesses by right-clicking on the CBSubs page before payment in your browser "Inspect", then selecting the "Network" tab, then try paying at sandbox. When that message "Things aren’t working as they should, try again." appears, you should see a POST network access like CreateBillingCart with result code "400". Look at the request Response tab, and you will probably see what the issue is (e.g. more than 52 recurrings or less than 2 (which is the SRT field of Paypal). E.g. I had in a test: ""data": {"TYPE": "INVALID_VALUE", "PARAM": "SRT", "VALUE": "60"}. In this case there were 60 recurrings, but Paypal supports only unlimited recurrings, or 2 to 52 recurrings....

Did you limit the number of recurings in your plan ? If yes to which number ?

Looking forward to your replies with information on those 2 issues (copy to clipboard your reply before sending it as they may trigger our firewall depending on its content).

Ok, I think I have fixed what I suspect were the causes for both issues in latest CBSubs nightly build.

The second issue was (I guessed) this one forge.joomlapolis.com/issues/8701 , also fixed in latest nightly.

Please upgrade CBSubs (backup, then CB Plugins->Install/Upgrade, then "Refresh" and "Upgrade all") to latest nighly build and re-test with the Paypal Sandbox.

Then if one of the two tests still doesn't work, I'll really need the information asked above for the corresponding issue.

If all is fixed, please reply too, just to confirm that both issues are now solved.