我将 Google App Engine 与 PHP 结合使用。
经过几个请求后，我收到以下错误
Fatal error: Uncaught exception 'google\net\ProtocolBufferEncodeError' with message 'Internal bug: Encoded size doesn't match predicted' in /base/data/home/runtimes/php/sdk/google/appengine/runtime/proto/ProtocolMessage.php:68
Stack trace:
#0 /base/data/home/runtimes/php/sdk/google/appengine/runtime/proto/ProtocolMessage.php(50): google\net\ProtocolMessage->serializePartialToString()
#1 /base/data/home/runtimes/php/sdk/google/appengine/runtime/RealApiProxy.php(52): google\net\ProtocolMessage->serializeToString()
#2 /base/data/home/runtimes/php/sdk/google/appengine/runtime/ApiProxy.php(42): google\appengine\runtime\RealApiProxy->makeSyncCall('taskqueue', 'BulkAdd', Object(google\appengine\TaskQueueBulkAddRequest), Object(google\appengine\TaskQueueBulkAddResponse), NULL)
#3 /base/data/home/runtimes/php/sdk/google/appengine/api/taskqueue/PushQueue.php(195): google\appengine\runtime\ApiProxy::makeSyncCall('taskqueue', 'BulkAdd', Object(google\appengine\TaskQueueBulkAddRequest), Object(google\appengine\TaskQueueBulkAddResponse in /base/data/home/runtimes/php/sdk/google/appengine/runtime/proto/ProtocolMessage.php on line 68
Fatal error: Uncaught exception 'google\net\ProtocolBufferEncodeError' with message 'Internal bug: Encoded size doesn't match predicted' in /base/data/home/runtimes/php/sdk/google/appengine/runtime/proto/ProtocolMessage.php:68
Stack trace:
#0 /base/data/home/runtimes/php/sdk/google/appengine/runtime/proto/ProtocolMessage.php(50): google\net\ProtocolMessage->serializePartialToString()
#1 /base/data/home/runtimes/php/sdk/google/appengine/runtime/RealApiProxy.php(52): google\net\ProtocolMessage->serializeToString()
#2 /base/data/home/runtimes/php/sdk/google/appengine/runtime/ApiProxy.php(42): google\appengine\runtime\RealApiProxy->makeSyncCall('taskqueue', 'BulkAdd', Object(google\appengine\TaskQueueBulkAddRequest), Object(google\appengine\TaskQueueBulkAddResponse), NULL)
#3 /base/data/home/runtimes/php/sdk/google/appengine/api/taskqueue/PushQueue.php(195): google\appengine\runtime\ApiProxy::makeSyncCall('taskqueue', 'BulkAdd', Object(google\appengine\TaskQueueBulkAddRequest), Object(google\appengine\TaskQueueBulkAddResponse in /base/data/home/runtimes/php/sdk/google/appengine/runtime/proto/ProtocolMessage.php on line 68
为了解决这个问题，我关闭了所有实例，代码正常加载。在几次请求之后，我又遇到了同样的致命错误。
什么会导致这个致命错误？以及我该如何解决。