Got an error on exporting Containers

[hissy]

Whoops\Exception\ErrorException thrown with message "count(): Parameter must be an array or an object that implements Countable"

Stacktrace:
#32 Whoops\Exception\ErrorException in /path/to/packages/migration_tool/elements/export/results/standard_list.php:4
#31 Whoops\Run:handleError in /path/to/packages/migration_tool/elements/export/results/standard_list.php:4
#30 include in /path/to/concrete/src/View/View.php:532
#29 Concrete\Core\View\View:element in /path/to/packages/migration_tool/src/PortlandLabs/Concrete5/MigrationTool/Exporter/Item/SearchResult/StandardFormatter.php:97
#28 PortlandLabs\Concrete5\MigrationTool\Exporter\Item\SearchResult\StandardFormatter:displaySearchResults in /path/to/packages/migration_tool/single_pages/dashboard/system/migration/add_to_export_batch.php:72
#27 include in /path/to/concrete/src/View/View.php:308
#26 Concrete\Core\View\View:renderInnerContents in /path/to/concrete/src/View/View.php:286
#25 Concrete\Core\View\View:renderViewContents in /path/to/concrete/src/View/AbstractView.php:164
#24 Concrete\Core\View\AbstractView:render in /path/to/concrete/src/Http/ResponseFactory.php:148
#23 Concrete\Core\Http\ResponseFactory:view in /path/to/concrete/src/Http/ResponseFactory.php:215
#22 Concrete\Core\Http\ResponseFactory:controller in /path/to/concrete/src/Http/ResponseFactory.php:367
#21 Concrete\Core\Http\ResponseFactory:collection in /path/to/concrete/src/Http/DefaultDispatcher.php:132
#20 Concrete\Core\Http\DefaultDispatcher:handleDispatch in /path/to/concrete/src/Http/DefaultDispatcher.php:60
#19 Concrete\Core\Http\DefaultDispatcher:dispatch in /path/to/concrete/src/Http/Middleware/DispatcherDelegate.php:39
#18 Concrete\Core\Http\Middleware\DispatcherDelegate:next in /path/to/packages/c5j_pageviews/src/PageViews/PageViewMiddleware.php:63
#17 C5JPageViews\PageViewMiddleware:process in /path/to/concrete/src/Http/Middleware/MiddlewareDelegate.php:50
#16 Concrete\Core\Http\Middleware\MiddlewareDelegate:next in /path/to/concrete/src/Http/Middleware/FrameOptionsMiddleware.php:39
#15 Concrete\Core\Http\Middleware\FrameOptionsMiddleware:process in /path/to/concrete/src/Http/Middleware/MiddlewareDelegate.php:50
#14 Concrete\Core\Http\Middleware\MiddlewareDelegate:next in /path/to/concrete/src/Http/Middleware/StrictTransportSecurityMiddleware.php:36
#13 Concrete\Core\Http\Middleware\StrictTransportSecurityMiddleware:process in /path/to/concrete/src/Http/Middleware/MiddlewareDelegate.php:50
#12 Concrete\Core\Http\Middleware\MiddlewareDelegate:next in /path/to/concrete/src/Http/Middleware/ContentSecurityPolicyMiddleware.php:36
#11 Concrete\Core\Http\Middleware\ContentSecurityPolicyMiddleware:process in /path/to/concrete/src/Http/Middleware/MiddlewareDelegate.php:50
#10 Concrete\Core\Http\Middleware\MiddlewareDelegate:next in /path/to/concrete/src/Http/Middleware/CookieMiddleware.php:35
#9 Concrete\Core\Http\Middleware\CookieMiddleware:process in /path/to/concrete/src/Http/Middleware/MiddlewareDelegate.php:50
#8 Concrete\Core\Http\Middleware\MiddlewareDelegate:next in /path/to/concrete/src/Http/Middleware/ApplicationMiddleware.php:29
#7 Concrete\Core\Http\Middleware\ApplicationMiddleware:process in /path/to/concrete/src/Http/Middleware/MiddlewareDelegate.php:50
#6 Concrete\Core\Http\Middleware\MiddlewareDelegate:next in /path/to/concrete/src/Http/Middleware/MiddlewareStack.php:86
#5 Concrete\Core\Http\Middleware\MiddlewareStack:process in /path/to/concrete/src/Http/DefaultServer.php:85
#4 Concrete\Core\Http\DefaultServer:handleRequest in /path/to/concrete/src/Foundation/Runtime/Run/DefaultRunner.php:125
#3 Concrete\Core\Foundation\Runtime\Run\DefaultRunner:run in /path/to/concrete/src/Foundation/Runtime/DefaultRuntime.php:102
#2 Concrete\Core\Foundation\Runtime\DefaultRuntime:run in /path/to/concrete/dispatcher.php:45
#1 require in /path/to/index.php:2