Sequence diagram is not generated in IntelliJ Ultimate

[kidomine]

Description:
Sequence diagram is not generated in IntelliJ Ultimate.

IDE emits the following error in idea.log:

"/Library/Ballerina/distributions/jballerina-1.2.7/bin/ballerina home" command. received output: Error: Ballerina is supported only on JDK 1.8`

Same error is emitted by the IDE when switching to Ballerina 1.2.5.
Note that running ballerina home directly via terminal is always successful:

$ballerina home
/Library/Ballerina/distributions/jballerina-1.2.7

Also, embedded JRE seems to be present as well: /Library/Ballerina/dependencies/jdk8u202-b08-jre

All other plugin functions seem to be working fine:

• syntax highlighting
• gutter icons for running the main/services files
• actual compile and execution seems OK as well

Steps to reproduce:
Option 1: Open any ballerina file.
Option 2: Create hello world project in IntelliJ, then open the .bal file

Regardless of the above options, the resulting sequence diagram is blank.

Affected Versions:

• Ballerina Distribution: 1.2.7, 1.2.5
• Ballerina IntelliJ plugin: 1.2.7, 1.2.5

OS, DB, other environment details and versions:

• OS: macOS 10.15.5
• IDE: IntelliJ Ultimate, 2020.2
• Java (JAVA_HOME): jdk1.8.0_45.jdk, jdk1.8.0_202.jdk
• IntelliJ Runtime: JBR JDK 11b125, JBR JDK 11.0.7+10-b944.20
• Also tried using same runtimes as listed under JAVA_HOME above

The following configuration on the same machine works fine:

• Ballerina Distribution: 1.2.5
• Ballerina IntelliJ plugin: 1.2.7, 1.2.5
• IntelliJ Community, 2019.3.5
• IntelliJ Runtime: JBR JDK 11.0.6+8-b520 x86_64
• Java (JAVA_HOME): JBR JDK 11.0.6+8-b520 x86_64, jdk1.8.0_45.jdk, jdk1.8.0_202.jdk

UPDATE 1:
Using IntelliJ CE 2020.2:

• default runtime (JBR JDK 11.0.7+10-b944 x86_64) also do not generate sequence diagram
• however, using same runtime as 2019.3.5 (JBR JDK 11.0.6+8-b520 x86_64) the diagram can be generated successfully (see additional screenshot below)

Related Issues (optional):
Maybe related or similar to #24.

Suggested Labels (optional):
Question, Bug, IntelliJ Plugin

Suggested Assignees (optional):

Screenshots:

• IntelliJ CE 2019.3.5 Build Information

• IntelliJ CE 2019.3.5 with Sample Code and Proper Sequence Diagram

• IntelliJ Ultimate 2020.2 with Sample Code and Empty Sequence Diagram

• UPDATE 1: IntelliJ CE 2020.2 with Sample Code and Proper Sequence Diagram (using default IntelliJ Runtime for 2019.3.5: JBR JDK 11.0.6+8-b520 x86_64)