Help needed - System.NullReferenceException: Object reference not set to an instance of an object.

[swidz]

I have noticed strange behaviour which leads to System.NullReferenceException: Object reference not set to an instance of an object when firing jobs.

I happens only with persistent store (checked on SQLServer and Microsoft-SQLite) and when Job class is in a separate assembly. With memory store everything works correctly. When job is defined inside asp.net project (where silkierquartz is hosted) also no problems. Only persistent store + external assembly.

I use Quartz.Net 3.7.0 with SilkierQuartz 5.0.356
The project type is Asp.Net Core 7.0 with EFCore

SilkierQuartz have a feature to auto discover jobs decorated with SilkierQuartzAttribute.
It seems that for some reason auto discover will end up with NullReferenceException in case of persistent store and external job assembly

The workaround is to call .AddQuartzJob<JobClass>() which will create new job in service collection.
I have compared these two registration routines (auto discover and manually call AddQuartzJob) and there is not much of a difference.

I understand that it might be SilkerQuartz related issue but I am curious if you could lead me to possible causes or perhaps it is a known issue with Quartz.Net

The exceptrion from logs is as follows:

Job DEFAULT.ExecutionWorkerJobsMonitorJob threw an exception.
Quartz.SchedulerException: Job threw an unhandled exception.
 ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at Quartz.Core.JobRunShell.Run(CancellationToken cancellationToken)
   --- End of inner exception stack trace --- [See nested exception: System.NullReferenceException: Object reference not set to an instance of an object.
   at Quartz.Core.JobRunShell.Run(CancellationToken cancellationToken)]

I have described my issue here
System.NullReferenceException: Object reference not set to an instance of an object

and added a working example presenting the issue based on SilkierQuartz example project
SilkierQuartz fork with external assembly job and persistent storage

Best regards,
Sebastian

[swidz]

For posterity,
I have found the solution. The issue was how assembly list was loaded that was passed to services.AddSilkierQuartz
To create that list, I used a helper method that internally used System.Reflection.Assembly.Load(assemblyName)
or System.Reflection.Assembly.LoadFile(assemblyPath)

but instead it should use

System.Runtime.Loader.AssemblyLoadContext.Default.LoadFromAssemblyName(assemblyName) or
System.Runtime.Loader.AssemblyLoadContext.Default.LoadFromAssemblyPath(assemblyPath).

References:
About System.Runtime.Loader.AssemblyLoadContext

Regards,
Sebastian