Unexpected exeption

Hello, we got following exception. Do you know why the exception is thrown?

Exception in thread "Thread-39" com.objectdb.o.UserException: Failed to read from file 'C:\Users\DEVELO~1\AppData\Local\Temp\objectdb_6455242561764346615\pages19.dat'
	at com.objectdb.o.MSG.a(MSG.java:77)
	at com.objectdb.o.LFL.Yz(LFL.java:1163)
	at com.objectdb.o.LFL.Yz(LFL.java:1127)
	at com.objectdb.o.PCF.c(PCF.java:176)
	at com.objectdb.o.PAG.m(PAG.java:468)
	at com.objectdb.o.PAG.r(PAG.java:714)
	at com.objectdb.o.UPT.u(UPT.java:121)
	at com.objectdb.o.URT.g(URT.java:173)
	at com.objectdb.o.TSK.b(TSK.java:146)
	at com.objectdb.o.TSK.c(TSK.java:96)
	at com.objectdb.o.TSM.a(TSM.java:88)
	at com.objectdb.o.UTT.r(UTT.java:377)
	at com.objectdb.o.UTT.q(UTT.java:425)
	at com.objectdb.o.UTT.g(UTT.java:282)
	at com.objectdb.o.TSK.b(TSK.java:146)
	at com.objectdb.o.TSK.c(TSK.java:96)
	at com.objectdb.o.MST.Zc(MST.java:1180)
	at com.objectdb.o.IXA$1.run(IXA.java:418)
Caused by: java.io.IOException: Stream Closed
	at java.base/java.io.RandomAccessFile.seek0(Native Method)
	at java.base/java.io.RandomAccessFile.seek(Unknown Source)
	at com.objectdb.o.LFL.Yz(LFL.java:1154)
	... 16 more

the affected ObjectDB version is 2.8.0.b04

we get also another exception sometimes:

Exception in thread "Thread-39" java.lang.NullPointerException
    at com.objectdb.o.LFL.YC(LFL.java:987)
    at com.objectdb.o.LFL.YC(LFL.java:962)
    at com.objectdb.o.FIW.ZS(FIW.java:96)
    at com.objectdb.o.FIW.S(FIW.java:57)
    at com.objectdb.o.DSS.F(DSS.java:942)
    at com.objectdb.o.DSS.j(DSS.java:723)
    at com.objectdb.o.DSS.ZR(DSS.java:699)
    at com.objectdb.o.MST.Zc(MST.java:1181)
    at com.objectdb.o.IXA$1.run(IXA.java:418)

The stack traces are related to issues with writing and reading from that database file.

More information is needed. Could you please check the database file with the ObjectDB Doctor for errors? Can you reproduce the exception by following specific actions?

I repaired the db file with the dbdoctor. But the issue does also occur with the repaired db.

The issue is not always reproducible. Sometimes the use case runs through without exception. But most of the time the issue occurs.

Could you please send the information that was written to the log file when the exceptions were thrown as well as the Doctor output?

Is it an issue only with a specific database file?
Can you think of anything special in that database file?