APP: Aria2-1.28 windows x64
OS: Windows 10 Enterprise LTSB 2016 14393.351 x64
CONF: https://github.com/jc3213/Misc/raw/767c3336a7bb49a1cb7f6e507656091f93d42d35/Aria2/aria2.conf

It happens randomly that aria2c.exe eat up 26~28% of My CPU (Core i5-4460) and the command line window get frozen. Then the Aria2 WebUI started to report that Oh Snap! Could not connect to the aria2 RPC server. Will retry in 10 secs. You might want to check the connection settings by going to Settings > Connection Settings

The aria2.p12 I use is generated by OpenSSL following the instruction from IBM http://www.ibm.com/support/knowledgecenter/en/SSWHYP_4.0.0/com.ibm.apimgmt.cmc.doc/task_apionprem_gernerate_self_signed_openSSL.html

Here's the screenshot

I'm reading ziahamza/webui-aria2#108 and tried to generated another aria2.p12 certification. Hope this will work