On uploading a CSV file the page theming breaks.

This patch shows the default checkboxes, textfields and buttons

I'm unclear about the patch in #5 however this didn't work for me.

What I found was when the error log was not formatted properly this occurred.
We noticed this when transitioning from PHP 7.4 -> 8.1

I have resolved it by addressing https://git.drupalcode.org/project/commerce_smart_importer/-/blob/8.x-1....
and testing to ensure that what we are interating over is an array.

It looks like it's expected that there will be in $fields_log a number of non numeric keys which indicate errors/flags/warnings as a whole as well as numeric keys that relate to specific fields.

Note you might also spot this if you upload a CSV with an incorrect number of header rows . Make sure the header does exactly match the template file you download.