System.Data.SQLite

We intermittently experience an AccessViolationException while acessing an open reader in our .NET Core 3.1 based windows service.
Basically we use a single shared SQLite connction accross many TPL Dataflow tasks which works fine. The database is operated in WAL mode and the serialized isolation mode is implicitly used. However, after several hours of operation and millions of data rows written into the database an access violation occurs in SQLite.Interop.dll.

Unhandled exception at 0x00007FF8CCC54618 (SQLite.Interop.dll) in Service__PID__4772__Date__06_29_2020__Time_02_42_55PM__613__First Chance Access Violation.dmp: 0xC0000005: Access violation reading location 0x0000000000000011. occurred

DebugDiag Log:
....
***********************
*  EXCEPTION DETAILS  *
***********************

DetailID = 1
	Count:    1
	Exception #:  0XC0000005
	Stack:        
		0x00007ff8`702c5d64
		e entries
		e entries
		e entries
		coreclr!GetCLRRuntimeHost+0x31d7a0
		e entries
		e entries
		e entries
		0x00007ff8`702c5cc7
		e entries


DetailID = 2
	Count:    1
	Exception #:  0XC0000005
	Stack:        
		KERNELBASE!RaiseException+0x68
		coreclr!coreclr_shutdown_2+0xba49
		coreclr!coreclr_shutdown_2+0xba7b
		e entries
		e entries
		coreclr!coreclr_shutdown_2+0xba85
		e entries
		e entries
		e entries
		0x00007ff8`702c5d64
		e entries
		e entries
		e entries
		coreclr!GetCLRRuntimeHost+0x31d7a0
		e entries
		e entries
		e entries
		0x00007ff8`702c5cc7
		e entries


DetailID = 3
	Count:    10
	Type:     NOT_FOUND
	Message:  
	Stack:    


DetailID = 4
	Count:    21062
	Type:     NOT_FOUND
	Message:  
	Stack:    
		(omitted)

DetailID = 5
	Count:    1
	Exception #:  0XC0000005
	Stack:        
		SQLite_Interop!sqlite3_blob_read+0xd8
		e entries
		e entries
		SQLite_Interop!sqlite3_blob_read+0x15
		e entries
		e entries
		e entries
		0x00007ff8`70ab0f79
		e entries
		0xa7eae1
		0x0000028a`00000001
		0x0000028a`4be09030
		0x1
		0x00008ff0`a2f3c1c0
		coreclr!GetCLRRuntimeHost+0x249148
		0x000000ae`1227fa90
		0x00007ff8`70444328
		0x00007ff8`70444328
		e entries
		e entries
		0x000000ae`1227f030
		e entries
		e entries
		e entries
		0x00007ff8`70ab0f79
		e entries
		0x000000ae`1227f0e0
		0x000000ae`1227f710
		0x00007ff8`70444328
		0x0000028a`51a19998
		0x0000028a`4d0f3928
		0x0000028a`51a19970
		0x0000028a`51a19998
		0x000000ae`1227f710
		0x000000ae`1227f870
		0x1
		0x0000028a`51872390
		e entries
		e entries
		0x000000ae`1227f150
		e entries
		e entries
		e entries
		0x00007ff8`70924471
		e entries





***********************
*  EXCEPTION SUMMARY  *
***********************

	|-----------------------|
	| Count | Exception     |
	|-----------------------|
	| 21072 | CLR Exception |
	| 3     | 0XC0000005    |
	|-----------------------|


**** Some exception details were omitted due to the following reasons
	The maximum number of stacks (MAX_CLR_EXCEPTION_STACKS_PER_EXCEPTION_TYPE = 10) for this CLR exception type have been collected: 'NOT_FOUND'

Debugging Overhead Cost:
	Total Elapsed Ticks = 25495703 (100%)
	Total Ticks Spent in Debugger Engine = 1923 (0%)
	Total Ticks Spent in Crash Rule Script = 124536 (0%)
***********************





Since still unable to reproduce this error in an isolated environment I only can provide a scarse amount of information.
Any help would be highly appreciated.

The stack traces do not really contain enough information to pin this
issue down.

However, given your description of the issue, I'm wondering if you are
using System.Data.SQLite objects (SQLiteConnection, SQLiteCommand, and
SQLiteDataReader) from multiple threads.  In general, this is not a good
idea as those objects are not thread-safe, even if the underlying native
SQLite library is configured for full thread safety (which it is).