I getting error 500 on a popup (There was an error sending the request! Error: HTTP error! status: 500) when oppening General Setting also when saving records.

Also on a multirecord editor with file upload I'm getting Fatal error: Allowed memory size and  uber_file_get_contents(): Return value must be of type string|false.

The mysqli object working like a charm y will check mysql_escape() function.

ob_start();
include 'calificaciones_save_post.php';
$output = ob_get_clean();
if (mysqli()->query($output)) {
    header("Location: alumnos.php");
die();
} else {
    dieAsCaller("MySQL Error: ". htmlencode(mysqli()->error) . "\n");
}

$conexion = mysqli_connect("localhost","user","pass","database");
if(!$conexion){
	die('No se puede conectar '.mysql_error());
	}
if (mysqli_query($conexion, $output )) {
    header("Location: alumnos.php");
die();
} else {
    echo mysqli_error($conexion);
}
mysqli_close ($conexion);

<?php foreach ($asignaturasRecords as $record): ?>
      <?php $num = $record['num']; ?>
	  <?php echo "('" . $_POST["createdDate_$num"] . "',"; ?>
	  <?php echo "'" . $_POST["createdByUserNum_$num"] . "',"; ?>
	  <?php echo "'" . $_POST["updatedDate_$num"] . "',"; ?>
	  <?php echo "'" . $_POST["updatedByUserNum_$num"] . "',"; ?>
	  <?php echo "'" . $_POST["curp_$num"] . "',"; ?>
	  <?php echo "'" . $_POST["claveasignatura_$num"] . "',"; ?>
	  <?php echo "'" . $_POST["ciclo_$num"] . "',"; ?>
	  <?php echo "'" . $_POST["calificacion_$num"] . "',"; ?>
	  <?php echo "'" . $_POST["idobservaciones_$num"] . "'),"; ?>
<?php endforeach ?>

('2023-03-16 03:31:12', '1', '2023-03-16 03:31:12', '1', 'TFAR960722HDFESD10', 'LP946', '2020', '9.4', '100'),
('2023-03-16 03:31:12', '1', '2023-03-16 03:31:12', '1', 'TFAR960722HDFESD10', 'LP947', '2020', '9.4', '100'),
('2023-03-16 03:31:12', '1', '2023-03-16 03:31:12', '1', 'TFAR960722HDFESD10', 'LP948', '2020', '9.4', '100'),
('2023-03-16 03:31:12', '1', '2023-03-16 03:31:12', '1', 'TFAR960722HDFESD10', 'LP499', '2020', '9.4', '100'),
('2023-03-16 03:31:12', '1', '2023-03-16 03:31:12', '1', 'TFAR960722HDFESD10', 'LP950', '2020', '9.4', '100'),

UPDATE
--------------------
I was trying to use str_replace or substr_replace but does not work, I get that doesn't work as the value is an array.
Also tried

foreach ($asignaturasRecords as $record => $element) {
    if ($record === array_key_first($array)) {
        echo "'" . $_POST["idobservaciones_$num"] . "'),";
    }

    if ($record === array_key_last($array)) {
        echo "'" . $_POST["idobservaciones_$num"] . "');";
    }
}

Notice: session_start(): ps_files_cleanup_dir: opendir(/tmp/.priv) failed: Permission denied (13) in /homepages/14/d850035105/htdocs/mpanel/lib/init.php on line 735 Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /homepages/14/d850035105/htdocs/mpanel/lib/init.php:735) in /homepages/14/d850035105/htdocs/mpanel/lib/init.php on line 735 Fatal error: Couldn't start session! 'session_start(): Cannot send session cache limiter - headers already sent (output started at /homepages/14/d850035105/htdocs/mpanel/lib/init.php:735)'! in /homepages/14/d850035105/htdocs/mpanel/lib/init.php on line 735

Any help would be great.

if (!$errorsAndAlerts) {
  $emailHeaders = emailTemplate_loadFromDB(array(
    'template_id'        => 'TEST-MAIL-ME',
    'addHeaderAndFooter' => false,
    'placeholders'       => array(
      'visitor.name'      => $fullname,
      'visitor.email'     => $email,
      'visitor.phone'     => $phone,
      'visitor.message'   => $message,
      'visitor.agree'     => $agree,
    ),
  ));

$accessWhere .= " AND `num` != '1' ";

<?php // if record show this
 if ($record['record']): ?>
<?php echo htmlencode($record['record']) ?>

<?php // if no record show this
 else: ?>
<?php echo "Colleague"; ?>
<?php endif ?>

First of all thank you for the reply, the code is still not working, I upload the file to plugins folder, then I activate the plugin and set Required Plugins at the Advanced tab on Section Editors.

I tried to use the following code but is not working

<?php
/*
Plugin Name: Administracion
Description: Acceso administracion de usuarios
Version: 1.00
CMS Version Required: 3.00
*/

addFilter('list_where', 'filterUser', null, 2);

function filterUser($accessWhere, $tableName) {
  /* only check the accounts section */
  if ($tableName == 'accounts') { return $accessWhere; }
  
  $accessWhere .= " AND 'num' != '1' ";
  return $accessWhere;
}

?>

<iframe src='cmsb/3rdParty/uploadForm3_iframe.php?table=<?php echo $tableName ?>&amp;field=upload&amp;num=<?php echo $recordNum ?>&amp;preSaveTempId=<?php echo $FORM_PRESAVETEMPID ?>'
            height='100' width='600' frameborder='0' scrolling='no'>
</iframe>

$allowedTables = array('every_field_multi');
$allowedFields = array('upload');

to

$allowedTables = array($table);
$allowedFields = array($field);

a_o  is the year field

I look that years are in descending order in that output.

<?php
  require_once "/lib/viewer_functions.php";
  list($transparenciaRecords, $transparenciaMetaData) = getRecords(array(
    'tableName'   => 'transparencia',
    'allowSearch' => '0',
    'orderBy' => 'a_o DESC, carpeta'
  ));
?>

http://preview.ibb.co/b3vQWv/Ashampoo_Snap_2017_09_05_22h35m06s_001.png

https://preview.ibb.co/nx8r3a/Ashampoo_Snap_2017_09_04_19h52m13s_001.png

Please help me.

<?php foreach ($transparenciaRecords as $record): ?><?php if(!in_array(strtolower($record['a_o']), $alreadyListed)): ?><div class="block">
<div class="container">
<h2 class="block-title block-title--single">Transparencia <?php echo $record['a_o'] ?></h2>
</div>
</div><?php $alreadyListed[] = strtolower($record['a_o']); ?>
<?php endif; ?>
<div class="block">
<div class="container">
<!-- Wide table with range of cols -->
<div class="table-responsive">
<table class="table table-bordered table--wide table-present">
<colgroup class="col-sm-width">
</colgroup><colgroup class="col-sm-width">
</colgroup><thead>
<tr>
<th>Documento</th>
<th>Descarga</th>
</tr>
</thead>

<tbody>
<tr>
<td><?php echo $record['a_o'] ?> - <?php echo $record['carpeta'] ?> - <?php echo $record['titulo'] ?></td>
<td><a class="btn btn-primary btn-sm" target="_blank" href="<?php foreach ($record['archivo'] as $upload): ?>
<?php
$extension = $upload['extension'];
if($extension == 'pdf' || $extension == 'rar') {
echo $upload['urlPath'];
} else {
echo "https://view.officeapps.live.com/op/view.aspx?"; echo $upload['filename'];
}
?><?php endforeach ?>">Ver Documento</a></td>
</tr>
<?php endforeach ?>

Are you using a plugin??