This group field is as follows:
<?php
$groups = rwmb_meta( 'resources_group' );
foreach ( $groups as $group ) {
// Field resource_or_database_type:
echo $group[ 'resource_or_database_type' ] ?? '';
// Field name_of_resource:
echo $group[ 'name_of_resource' ] ?? '';
// Field resource_details:
echo $group[ 'resource_details' ] ?? '';
// Field resource_link:
echo $group[ 'resource_link' ] ?? '';
}
?>
Which is a select, text, textarea, URL
In one case, the error showed when there were 3 group field values, that were filled as follows
FIRST GROUP FIELD CONFIG
1. Select: Value there, but not outputted
2. Text: TRUE
3. Text area: FALSE
4. URL: TRUE
SECOND GROUP FIELD CONFIG
1. Select: Value there, but not outputted
2. Text: TRUE
3. Text area: FALSE
4. URL: TRUE
THIRD GROUP FIELD CONFIG
1. Select: Value there, but not outputted
2. Text: TRUE
3. Text area: TRUE
4. URL: TRUE
The error showed beneath the first two fields, which had no value in the text area. When I added a space as the value in the text area for the first two, the error still showed. When the text area field was taken out of the Meta Box Group Skin template, no error showed.
I think the error is due to there being no value in a field.