Jenkins doesn't start after plugin update

Hi,

Every time after restarting Jenkins due to updates of plugins, the web page stucks in "Please wait while Jenkins is getting ready to work...". I only can resolve this by restarting the corresponding Windows service manually. This is my system configuration:
Jenkins: 2.27
OS: Windows Server 2012 R2
RAM: 4 GB

The attached documents cover the reports of jmap and jstack.

Are there any suggestions how to solve this issue?

Regards
mu88