So, YouTube isn't going to cooperate with your embeds anymore..?
There's a 'quick' solution, just disable 'lookups' in the Aeva settings. This should help, although you'll still have to manually modify protocols to 'http://' instead of 'https://' when posting a video.

If you want a full-fledged fix, you'll have to do with my diff patches. I'll post updated versions of the AeMe 2.10 files, too, but please remember not to share these outside of this board. Feel free to share the diff patches, though.
If you didn't change the original AeMe files, then feel free to just dropped the fixed files into your Sources folder.
Or, of course, switch to Wedge.

Important note: I only spent an hour or so on this fix. It's quite ugly, as it was backported from the Wedge codebase, and I didn't bother to make many tests for the Aeva-Embed.php changes.

--- Sources\Subs-Aeva-Sites.php 2010-10-08 11:56:08.000000000 +-0200
+++ Sources\Subs-Aeva-Sites.php 2015-05-13 16:07:02.000000000 +-0200
@@ -139,27 +139,27 @@
  array(
  'id' => 'ytb',
  'title' => 'YouTube',
  'website' => 'http://www.youtube.com',
  'type' => 'pop',
  'added' => '<4.0',
- 'pattern' => 'http://(?:video\.google\.(?:com|com?\.[a-z]{2}|[a-z]{2})/[^"]*?)?(?:(?:www|[a-z]{2})\.)?youtube\.com/[^"#[]*?(?:&|&amp;|/|\?|;|\%3F|\%2F)(?:video_id=|v(?:/|=|\%3D|\%2F))([\w-]{11})',
- 'movie' => 'http://www.youtube.com/v/$2&rel=0&fs=1',
+ 'pattern' => 'https?://(?:video\.google\.(?:com|com?\.[a-z]{2}|[a-z]{2})/[^"]*?)?(?:(?:www|[a-z]{2})\.)?youtube\.com/[^"#[]*?(?:&|&amp;|/|\?|;|\%3F|\%2F)(?:video_id=|v(?:/|=|\%3D|\%2F))([\w-]{11})',
+ 'movie' => '[url]https://www.youtube.com/v/[/url]$2&rel=0&fs=1',
  'size' => array(
  'normal' => array(480, 385),
  'ws' => array(640, 385),
  ),
  'ui-height' => 25,
  // http://www.youtube.com/watch?v=-X8mD76W4F0 or v=MxGofCFHYCc (all hail Jochen Hippel!)
  // On Google - http://video.google.co.uk/url?docid=-8978185459530152475&ev=v&len=91&srcurl=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dg2cT5J0gxeU
  // http://www.youtube.com/watch?v=M29NUeffJNA - Example of "Embedding Disabled By Request"
- 'fix-html-pattern' => '<object [^>]*><param name="movie" value="http://www\.youtube\.com/v/([\w-]{11})(?:&[^"]*)?">.*?</object>',
- 'fix-html-url' => 'http://www.youtube.com/watch?v=$1',
- 'lookup-url' => 'http://(?:video\.google\.(?:com|com?\.[a-z]{2}|[a-z]{2})/[^"]*?)?(?:(?:www|[a-z]{2})\.)?youtube\.com/[^"#[]*?(?:&|&amp;|/|\?|;|\%3F|\%2F)(?:video_id=|v(?:/|=|\%3D|\%2F))([\w-]{11})[^]#[]*',
- 'lookup-actual-url' => 'http://gdata.youtube.com/feeds/api/videos/$1?v=2',
- 'lookup-final-url' => 'http://www.youtube.com/watch?v=$1',
+ 'fix-html-pattern' => '<object [^>]*><param name="movie" value="https?://www\.youtube\.com/v/([\w-]{11})(?:&[^"]*)?">.*?</object>',
+ 'fix-html-url' => '[url]https://www.youtube.com/watch?v=[/url]$1',
+ 'lookup-url' => 'https?://(?:video\.google\.(?:com|com?\.[a-z]{2}|[a-z]{2})/[^"]*?)?(?:(?:www|[a-z]{2})\.)?youtube\.com/[^"#[]*?(?:&|&amp;|/|\?|;|\%3F|\%2F)(?:video_id=|v(?:/|=|\%3D|\%2F))([\w-]{11})[^]#[]*',
+ 'lookup-actual-url' => '[url]https://www.googleapis.com/youtube/v3/videos?id=[/url]$1',
+ 'lookup-final-url' => '[url]https://www.youtube.com/watch?v=[/url]$1',
  'lookup-title' => true,
  'lookup-title-skip' => true,
  'lookup-pattern' => array(
  'id' => '<id>.*?:([\w-]+)</id>',
  'error' => '<internalReason>(.*?)</internalReason>',
  'noexternalembed' => '<yt:accessControl\saction=\'embed\'\spermission=\'denied\'/>',
@@ -160,19 +160,19 @@
  'lookup-title' => true,
  'lookup-title-skip' => true,
  'lookup-pattern' => array(
  'id' => '<id>.*?:([\w-]+)</id>',
  'error' => '<internalReason>(.*?)</internalReason>',
  'noexternalembed' => '<yt:accessControl\saction=\'embed\'\spermission=\'denied\'/>',
  'id' => 'ytp',
  'title' => 'YouTube (Playlists)',
  'website' => 'http://www.youtube.com',
  'type' => 'pop',
  'added' => '<4.0',
  // http://uk.youtube.com/view_play_list?p=7262E1895FA61B39
- 'pattern' => 'http://(?:(?:www|[a-z]{2})\.)?youtube\.com/[^"]*?(?:&|&amp;|/|\?|;)(?:id=|p=|p/)([0-9a-f]{16})',
+ 'pattern' => 'https?://(?:(?:www|[a-z]{2})\.)?youtube\.com/[^"]*?(?:&|&amp;|/|\?|;)(?:id=|p=|p/)([0-9a-f]{16})',
  'movie' => 'http://www.youtube.com/p/$2&rel=0&fs=1',
  'size' => array(480, 385),
  'ui-height' => 25,
  'fix-html-pattern' => '<object [^>]*><param name="movie" value="$1" />.*?</object>',
  ),
  array(
Then...

--- Sources\Aeva-Embed.php 2010-11-19 11:29:34.000000000 +-0200
+++ Sources\Aeva-Embed.php 2015-05-13 16:00:29.000000000 +-0200
@@ -106,13 +106,13 @@
  // For each enabled site to the end, attempt to embed
  for ($upto = 0; $upto < $j; $upto++)
  {
  $message = aeva_match($message);
 
  // If no active http links remain (making further embedding impossible), then stop
- if (stripos($message, '<a href="http://') === false)
+ if (stripos($message, '<a href="http') === false)
  break;
  }
 
  // Reverse protections and return the finished embedded content
  return aeva_reverse_protection(str_replace('<aeva-begin>', '', $message));
 }
@@ -113,28 +113,28 @@
  break;
  }
 
  // Reverse protections and return the finished embedded content
  return aeva_reverse_protection(str_replace('<aeva-begin>', '', $message));
 }
  }
 
  // Tidy up
  unset($unaltered);
 
  // No links remaining?  No further embedding possible, so set this variable before we return
- if ($reverse === true && stripos($input, '<a href="http://') === false)
+ if ($reverse === true && stripos($input, '<a href="http') === false)
  $context['aeva']['skip'] = true;
 
  return $input;
 }
 
 // Protect noembed & autolink items from embedding *before* BBC parsing - wrap quotes, but don't protect
 function aeva_preprotect(&$message, $cache_id)
 {
- if ((stripos($message, 'http://') === false && stripos($message, '') === false) || strpos($cache_id, 'sig') !== false)
+ if ((stripos($message, '://') === false && stripos($message, '') === false) || strpos($cache_id, 'sig') !== false)
  return;
 
  global $modSettings, $context;
 
  if (!empty($modSettings['cache_enable']))
  {
@@ -202,19 +202,19 @@
  return;
 
  global $modSettings, $context;
 
  if (!empty($modSettings['cache_enable']))
  {
 
  // Should haven't got here if autolinking of urls is disabled
  if (empty($modSettings['autoLinkUrls']))
  return $input;
 
  // Parse any URLs....
- if (preg_match('~http://|www\.~i', $input))
+ if (preg_match('~https?://|www\.~i', $input))
  {
  // Modified from SMF code, adding support for [center], [li], [td] and closing tags.
  $input = strtr($input, array('&#039;' => '\'', '&quot;' => '>">', '"' => '<"<', '&lt;' => '&lt;'));
  $input = preg_replace(
  array(
  '`(^|[\s>\.(;\'"]|\[(?:center|li|td|youtube|/\w+)])((?:http|https|ftp|ftps)://[\w%@:|-]+(?:\.[\w%-]+)*(?::\d+)?(?:/[\w\~%\.@,\?&;=#+:\'\\\\-]*|[\(\{][\w\~%\.@,\?&;=#(){}+:\'\\\\-]*)*[/\w\~%@\?;=#}\\\\-]?)`i',
@@ -705,19 +705,19 @@
  {
  // Modified from SMF code, adding support for [center], [li], [td] and closing tags.
  $input = strtr($input, array('&#039;' => '\'', '&quot;' => '>">', '"' => '<"<', '&lt;' => '&lt;'));
  $input = preg_replace(
  array(
  '`(^|[\s>\.(;\'"]|\[(?:center|li|td|youtube|/\w+)])((?:http|https|ftp|ftps)://[\w%@:|-]+(?:\.[\w%-]+)*(?::\d+)?(?:/[\w\~%\.@,\?&;=#+:\'\\\\-]*|[\(\{][\w\~%\.@,\?&;=#(){}+:\'\\\\-]*)*[/\w\~%@\?;=#}\\\\-]?)`i',
  global $context, $modSettings, $txt, $aeva_timer;
 
  $aeva_timer = (isset($aeva_timer) ? (int) $aeva_timer : 0) - array_sum(explode(' ', microtime()));
 
  if (strlen($message) > 10 & empty($context['uninstalling']))
  {
- if (!empty($modSettings['aeva_enable']) && empty($context['aeva_disable']) && stripos($message, 'http://') !== false && $smileys !== 'print' && strpos($cache_id, 'sig') === false)
+ if (!empty($modSettings['aeva_enable']) && empty($context['aeva_disable']) && stripos($message, '://') !== false && $smileys !== 'print' && strpos($cache_id, 'sig') === false)
  $message = aeva_main($message);
  else
  {
  // Removes any noembed
  $message = aeva_protection(
  array('noembed' => false),
@@ -1070,27 +1070,27 @@
  $message = aeva_main($message);
  else
  {
  // Removes any noembed
  $message = aeva_protection(
  array('noembed' => false),
  global $embed_album, $embed_folder, $context, $force_id;
 
  $link = preg_replace(array('~\[url=([^]]*)]([^[]*)\[/url]~', '~\[url]([^[]*)\[/url]~'), array('$1', '$1'), $link);
  $thumbs = array(
  'YouTube' => array(
  'func' => 'youtubeCreateThumb',
- 'pattern' => 'http://(?:video\.google\.(?:com|com?\.[a-z]{2}|[a-z]{2})/[^"]*?)?(?:(?:www|[a-z]{2})\.)?youtube\.com/[^"#[]*?(?:&|&amp;|/|\?|;|\%3F|\%2F)(?:video_id=|v(?:/|=|\%3D|\%2F))([\w-]{11})',
+ 'pattern' => 'https?://(?:video\.google\.(?:com|com?\.[a-z]{2}|[a-z]{2})/[^"]*?)?(?:(?:www|[a-z]{2})\.)?youtube\.com/[^"#[]*?(?:&|&amp;|/|\?|;|\%3F|\%2F)(?:video_id=|v(?:/|=|\%3D|\%2F))([\w-]{11})',
  ),
  'Dailymotion' => array(
  'func' => 'dailymotionCreateThumb',
  'pattern' => 'http://(?:www\.)?dailymotion\.(?:com|alice\.it)/(?:[^"]*?video|swf)/([a-z0-9]{1,18})',
  ),
  'GoogleVideo' => array(
  'func' => 'googleCreateThumb',
- 'pattern' => 'http://video\.google\.(com|com?\.[a-z]{2}|[a-z]{2})/(?:videoplay|url|googleplayer\.swf)\?[^"]*?docid=([\w-]{1,20})',
+ 'pattern' => 'https?://video\.google\.(com|com?\.[a-z]{2}|[a-z]{2})/(?:videoplay|url|googleplayer\.swf)\?[^"]*?docid=([\w-]{1,20})',
  ),
  'GoogleMaps' => array(
  'func' => 'gmapsCreateThumb',
  'pattern' => 'http://maps\.google\.[^">]+/\w*?\?[^">]+',
  ),
  'MetaCafe' => array(

The code I posted above was for AeMe 2.10, not Wedge. I believe it also works without changes for v1.4... Make sure to apply the diff manually for best results! And feel free to share your updated files if they're not identical.

Hello!

SMF 2.0.15 + Aeva Media 2.10 on PHP 5.6 = work Youtube.

SMF 2.0.15 + Aeva Media 2.10 on PHP 7.0 = not work Youtube.
On-screen text Youtube: "An error occurred. Please try again later (playback ID=...)"

Please, help?