Names have been changed below to protect the innocent

[SSH git-receive-pack /org/project.git (exampleuser)] ERROR com.google.gerrit.sshd.BaseCommand : Internal server error (user exampleuser account 123456) during git-receive-pack '/org/project.git'
com.google.gerrit.sshd.BaseCommand$Failure: fatal: Unpack error, check server log
	at com.google.gerrit.sshd.commands.Receive.runImpl(Receive.java:128)
	at com.google.gerrit.sshd.AbstractGitCommand.service(AbstractGitCommand.java:108)
	at com.google.gerrit.sshd.AbstractGitCommand.access$000(AbstractGitCommand.java:32)
	at com.google.gerrit.sshd.AbstractGitCommand$1.run(AbstractGitCommand.java:73)
	at com.google.gerrit.sshd.BaseCommand$TaskThunk.run(BaseCommand.java:488)
	at com.google.gerrit.server.logging.LoggingContextAwareRunnable.run(LoggingContextAwareRunnable.java:110)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304)
	at com.google.gerrit.server.git.WorkQueue$Task.run(WorkQueue.java:610)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.io.IOException: Unpack error on project "org/project":
  AdvertiseRefsHook: org.eclipse.jgit.transport.AdvertiseRefsHookChain@5ed46d67class org.eclipse.jgit.transport.AdvertiseRefsHookChain

	at com.google.gerrit.sshd.commands.Receive.runImpl(Receive.java:127)
	... 12 more
Caused by: org.eclipse.jgit.errors.UnpackException: Exception while parsing pack stream
	at org.eclipse.jgit.transport.ReceivePack.service(ReceivePack.java:2194)
	at org.eclipse.jgit.transport.ReceivePack.receive(ReceivePack.java:2120)
	at com.google.gerrit.sshd.commands.Receive.runImpl(Receive.java:98)
	... 12 more
Caused by: org.eclipse.jgit.errors.MissingObjectException: Missing tree examplesha1hashhere
	at org.eclipse.jgit.internal.transport.connectivity.FullConnectivityChecker.checkObjects(FullConnectivityChecker.java:196)
	at org.eclipse.jgit.internal.transport.connectivity.FullConnectivityChecker.checkConnectivity(FullConnectivityChecker.java:52)
	at org.eclipse.jgit.transport.ReceivePack.checkConnectivity(ReceivePack.java:1545)
	at org.eclipse.jgit.transport.ReceivePack.receivePackAndCheckConnectivity(ReceivePack.java:1215)
	at org.eclipse.jgit.transport.ReceivePack.service(ReceivePack.java:2189)
	... 14 more