Flow diagrams not displaying consistently in 2024.2/3 (seems to be a JetBrains regression)

[Xander Victory]

1. Open a flow, see diagram generated
2. Open a 2nd or more flow, diagram does not show
3. Close original
4. Reopen original, diagram does not show
5. Restart of IDE will load the first diagram

Only thing in the log (even with the flow diagram debug flags) seems to be a coroutine bug

2024-12-12 10:28:45,766 [ 890672]   INFO - #c.i.u.i.UnindexedFilesIndexer - Finished for RTBA-Salesforce. Unindexed files update took 398ms; general responsiveness: ok; EDT responsiveness: ok
2024-12-12 10:28:45,777 [ 890683]   INFO - #c.i.o.p.MergingQueueGuiExecutor - Task finished: (dumb mode task) UnindexedFilesIndexer[RTBA-Salesforce, 0 files, reason: On refresh of files in RTBA-Salesforce]
2024-12-12 10:28:45,777 [ 890683]   INFO - #c.i.o.p.MergingQueueGuiExecutor - Running task: (dumb mode task) com.intellij.openapi.roots.impl.PushedFilePropertiesUpdaterImpl$MyDumbModeTask@424c6dff (reason: Push on VFS changes)
2024-12-12 10:28:45,784 [ 890690]   INFO - #c.i.o.p.MergingQueueGuiExecutor - Task finished: (dumb mode task) com.intellij.openapi.roots.impl.PushedFilePropertiesUpdaterImpl$MyDumbModeTask@424c6dff (reason: Push on VFS changes)
2024-12-12 10:28:45,787 [ 890693]   INFO - #c.i.o.p.DumbServiceImpl - exit dumb mode [RTBA-Salesforce]
2024-12-12 10:29:00,870 [ 905776]   INFO - #c.i.s.SettingsSyncBridge - Couldn't obtain event lock. Will retry later
2024-12-12 10:29:02,017 [ 906923]   INFO - #c.i.w.i.i.j.s.JpsGlobalModelSynchronizerImpl - Saving global entities com.intellij.platform.workspace.jps.entities.SdkEntity to files
2024-12-12 10:29:02,026 [ 906932]   INFO - #c.i.w.i.i.j.s.JpsGlobalModelSynchronizerImpl - Saving global entities com.intellij.platform.workspace.jps.entities.LibraryEntity to files
2024-12-12 10:29:02,077 [ 906983]   INFO - #c.i.c.ComponentStoreImpl - Saving Project(name=RTBA-Salesforce, containerState=COMPONENT_CREATED, componentStore=D:\8squad\RTBA-Salesforce)RunManager took 39 ms
2024-12-12 10:29:02,089 [ 906995]   INFO - #c.i.c.ComponentStoreImpl - Saving appFileTypeManager took 44 ms
2024-12-12 10:29:04,920 [ 909826]   INFO - #c.i.s.SettingsSyncBridge - Couldn't obtain event lock. Will retry later
2024-12-12 10:29:09,138 [ 914044]   WARN - #c.i.u.Alarm - Do not create alarm without coroutineScope: com.intellij.ui.jcef.JBCefOsrComponent.<init>(JBCefOsrComponent.java:52)
2024-12-12 10:29:16,977 [ 921883]   INFO - #c.i.w.i.i.j.s.JpsGlobalModelSynchronizerImpl - Saving global entities com.intellij.platform.workspace.jps.entities.SdkEntity to files
2024-12-12 10:29:16,980 [ 921886]   INFO - #c.i.w.i.i.j.s.JpsGlobalModelSynchronizerImpl - Saving global entities com.intellij.platform.workspace.jps.entities.LibraryEntity to files
2024-12-12 10:29:17,002 [ 921908]   INFO - #c.i.c.ComponentStoreImpl - Saving appFileTypeManager took 13 ms
2024-12-12 10:29:48,269 [ 953175]   INFO - #c.i.s.SettingsSyncBridge - Couldn't obtain event lock. Will retry later
2024-12-12 10:29:49,282 [ 954188]   INFO - #c.i.s.SettingsSyncBridge - Couldn't obtain event lock. Will retry later
2024-12-12 10:29:50,453 [ 955359]   WARN - #c.i.u.Alarm - Do not create alarm without coroutineScope: com.intellij.ui.jcef.JBCefOsrComponent.<init>(JBCefOsrComponent.java:52)
2024-12-12 10:29:57,154 [ 962060]   INFO - STDOUT - 1000
2024-12-12 10:29:57,999 [ 962905]   INFO - STDOUT - 1000
2024-12-12 10:29:58,286 [ 963192]   INFO - STDOUT - 1000
2024-12-12 10:29:59,127 [ 964033]   WARN - #c.i.u.Alarm - Do not create alarm without coroutineScope: com.intellij.ui.jcef.JBCefOsrComponent.<init>(JBCefOsrComponent.java:52)
2024-12-12 10:30:04,846 [ 969752]   INFO - #c.i.w.i.i.j.s.JpsGlobalModelSynchronizerImpl - Saving global entities com.intellij.platform.workspace.jps.entities.SdkEntity to files
2024-12-12 10:30:04,849 [ 969755]   INFO - #c.i.w.i.i.j.s.JpsGlobalModelSynchronizerImpl - Saving global entities com.intellij.platform.workspace.jps.entities.LibraryEntity to files
2024-12-12 10:30:04,871 [ 969777]   INFO - #c.i.c.ComponentStoreImpl - Saving Project(name=RTBA-Salesforce, containerState=COMPONENT_CREATED, componentStore=D:\8squad\RTBA-Salesforce)RunManager took 14 ms
2024-12-12 10:30:04,879 [ 969785]   INFO - #c.i.c.ComponentStoreImpl - Saving appFileTypeManager took 19 ms
2024-12-12 10:31:00,913 [1025819]   INFO - #c.i.s.SettingsSyncBridge - Couldn't obtain event lock. Will retry later
2024-12-12 10:31:04,244 [1029150]   WARN - #c.i.u.Alarm - Do not create alarm without coroutineScope: com.intellij.ui.jcef.JBCefOsrComponent.<init>(JBCefOsrComponent.java:52)
2024-12-12 10:31:06,237 [1031143]   WARN - #c.i.u.Alarm - Do not create alarm without coroutineScope: com.intellij.ui.jcef.JBCefOsrComponent.<init>(JBCefOsrComponent.java:52)
2024-12-12 10:31:12,011 [1036917]   WARN - #c.i.u.Alarm - Do not create alarm without coroutineScope: com.intellij.ui.jcef.JBCefOsrComponent.<init>(JBCefOsrComponent.java:52) 

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[Scott Wells]

Thanks for logging. I'm able to reproduce this, and after extensive experimentation, it seems that it's due to a change in either 2024.2/3 as everything works fine in 2024.1. Mermaid has been slightly updated across those versions, but 2024.1 and 2024.2 use the same version, and things work in 2024.1 and not in 2024.2, so I think I can safely isolate it to some behavioral change introduced in 2024.2. JetBrains has been changing the threading model extensively, so it's not entirely surprising, but what's really odd is that if you open a number of Flow files then close and reopen the project, they all render just fine. It's just when you open them individually that this behavior occurs.

I’ve logged the following bug with JetBrains:

https://youtrack.jetbrains.com/issue/IJSDK-2318

Hopefully they’ll be able to provide some insights into what’s happening and how it can/should be addressed.

[Scott Wells]

I've added some thoughts (but not a true fix) in the release notes for 2.3.4.9.