Major BUG after last plugin update – wp-admin/options .php Not Found

Same issue

We haven’t been able to reproduce either of the two issues on our test systems. Both the settings page and the checkout are working correctly. We were able to test both with the EU VAT Assistant 1.14.5.200709 and WooCommerce from 3.0 until 4.3.

In relation to the payment element, the EU VAT Assistant doesn’t affect the checkout page directly. On that page, it shows the VAT number and validates the VAT number when the customer types it. That should not trigger an infinite loop.

In addition to the above, neither the settings page, nor the checkout logic were changed in the last update, which makes it unlikely that a bug was introduced.

It’s possible that the actual cause of the issue is a conflict with another element. It could be something else that doesn’t “play nice” when the EU VAT Assistant is active. Going by exclusion could help finding the root cause. Here’s a simple way to do that:
1. Disable all the plugins, except WooCommerce and the EU VAT Assistant.
2. Switch to a basic theme (e.g. Storefront) to exclude issues that could be due to some custom code in the theme.
3. Try to reproduce the issue.
4. If the site works, switch back to the original theme and try again.
5. If the site works, enable one of the plugins disabled at step #1 and try again.
6. Repeat #5 until the issue appears again.

This should help finding the source of the conflict.

If you have the URL of a site on which the issue can be reproduced, we can have a look at it directly. It should be faster than going by trial and error, trying to trigger the same error.

Update
We might have found a possible cause of the issues you described. One of the 3rd party libraries used by the EU VAT Assistant (nuSOAP, used to communicate with the VIES service) was updated just before the release package for the plugin was built (but after the build was prepared for the tests, which use an older version) and the automated process picked up the new version. The new version seems to be buggy and it can cause “out of memory” errors in some cases.

The nuSOAP library is used both when saving settings, to validate merchant’s VAT number, and at checkout. If the library triggers an error in these cases, then those two pages may not work correctly.

We’re now going to release another build with the older version of the library, which was working correctly. That might be sufficient to fix the errors reported.

Great support.
Thanks a lot!

We just releases version 1.14.6.200717 of the EU VAT Assistant. It uses the previous version of the nuSOAP library, which should work correctly.

Nice support Diego, after this update everything works as expected.

Thanks for the confirmation. Glad to be of help.