Empty Project list and SSL error : Connection Reset

[stevemayster]

Jenkins and plugins versions report

Environment

Windows 2016
Gitlab Branch Source Plugin 644.va_a_66886e07b_5
Gitlab API Plugin 5.0.1-78.v47a_45b_9f78b_7 
Jenkins 2.383
GItlab EE  15  in Docker

What Operating System are you using (both controller, and any agents involved in the problem)?

Windows 2016

Reproduction steps

1. Install GItlab Branch Source Plugin
2. Add server and API token
3. Test connection successful
4. Create multi branch pipeline and try to add Project
5. Got empty Project
6. Going to Jenkins log and found:
   Exception caught:org.gitlab4j.api.GitLabApiException: javax.net.ssl.SSLProtocolException: Connection reset
   java.net.SocketException: Connection reset
   at java.base/java.net.SocketInputStream.read(SocketInputStream.java:186)
   at java.base/java.net.SocketInputStream.read(SocketInputStream.java:140)
   at java.base/sun.security.ssl.SSLSocketInputRecord.read(SSLSocketInputRecord.java:448)
   at java.base/sun.security.ssl.SSLSocketInputRecord.decode(SSLSocketInputRecord.java:165)
   at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:108)
   Caused: javax.net.ssl.SSLProtocolException: Connection reset

Expected Results

Project apperead in interface, scan multibranch pipeline successfully

Actual Results

Empty Project in Branch Sources, error - javax.net.ssl.SSLProtocolException: Connection reset

Anything else?

No response

[Turiok]

Hi @stevemayster,
Does your Gitlab use a self-signed SSL certificate?
If so, does your Java JVM contain the trusted certificates for your Gitlab?