SharePoint content source stuck on Paused by system

After pausing the running crawls via Powershell during a cumulative update I found out that our content sources had the status “Paused by system”. From the search administration it was impossible to continu/ unpause the crawling. To solve this you can use the following simple powershellscript in the SharePoint Management Shell.
$SearchSA = Get-SPEnterpriseSearchServiceApplication “Search Service Application”