diff --git a/build/Version.props b/build/Version.props
index 2bc53dd4cc..43c4a45de6 100644
--- a/build/Version.props
+++ b/build/Version.props
@@ -3,12 +3,12 @@
   <!-- Integration tests will ensure they match across the board -->
   <Import Project="ControlPanelVersion.props" />
   <PropertyGroup>
-    <TgsCoreVersion>5.12.2</TgsCoreVersion>
+    <TgsCoreVersion>5.12.3</TgsCoreVersion>
     <TgsConfigVersion>4.6.0</TgsConfigVersion>
     <TgsApiVersion>9.10.2</TgsApiVersion>
     <TgsApiLibraryVersion>10.4.1</TgsApiLibraryVersion>
-    <TgsClientVersion>11.4.2</TgsClientVersion>
-    <TgsDmapiVersion>6.4.4</TgsDmapiVersion>
+    <TgsClientVersion>11.4.3</TgsClientVersion>
+    <TgsDmapiVersion>6.4.5</TgsDmapiVersion>
     <TgsInteropVersion>5.6.1</TgsInteropVersion>
     <TgsHostWatchdogVersion>1.2.2</TgsHostWatchdogVersion>
     <TgsContainerScriptVersion>1.2.1</TgsContainerScriptVersion>
diff --git a/src/DMAPI/tgs.dm b/src/DMAPI/tgs.dm
index ab2d565991..d7f7deec74 100644
--- a/src/DMAPI/tgs.dm
+++ b/src/DMAPI/tgs.dm
@@ -1,6 +1,6 @@
 // tgstation-server DMAPI
 
-#define TGS_DMAPI_VERSION "6.4.4"
+#define TGS_DMAPI_VERSION "6.4.5"
 
 // All functions and datums outside this document are subject to change with any version and should not be relied on.
 
diff --git a/src/Tgstation.Server.Client/ApiClient.cs b/src/Tgstation.Server.Client/ApiClient.cs
index 649745b609..9913a10184 100644
--- a/src/Tgstation.Server.Client/ApiClient.cs
+++ b/src/Tgstation.Server.Client/ApiClient.cs
@@ -305,18 +305,26 @@ namespace Tgstation.Server.Client
 				if (content != null)
 					request.Content = content;
 
-				var headersToUse = tokenRefresh ? tokenRefreshHeaders! : headers;
-				headersToUse.SetRequestHeaders(request.Headers, instanceId);
+				try
+				{
+					var headersToUse = tokenRefresh ? tokenRefreshHeaders! : headers;
+					headersToUse.SetRequestHeaders(request.Headers, instanceId);
 
-				if (authless)
-					request.Headers.Remove(HeaderNames.Authorization);
+					if (authless)
+						request.Headers.Remove(HeaderNames.Authorization);
 
-				if (fileDownload)
-					request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue(MediaTypeNames.Application.Octet));
+					if (fileDownload)
+						request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue(MediaTypeNames.Application.Octet));
 
-				await Task.WhenAll(requestLoggers.Select(x => x.LogRequest(request, cancellationToken))).ConfigureAwait(false);
+					await Task.WhenAll(requestLoggers.Select(x => x.LogRequest(request, cancellationToken))).ConfigureAwait(false);
 
-				response = await httpClient.SendAsync(request, cancellationToken).ConfigureAwait(false);
+					response = await httpClient.SendAsync(request, cancellationToken).ConfigureAwait(false);
+				}
+				finally
+				{
+					// prevent content param from getting disposed
+					request.Content = null;
+				}
 			}
 
 			try
diff --git a/src/Tgstation.Server.Host/Components/Byond/ByondManager.cs b/src/Tgstation.Server.Host/Components/Byond/ByondManager.cs
index 49456d01ae..157107228a 100644
--- a/src/Tgstation.Server.Host/Components/Byond/ByondManager.cs
+++ b/src/Tgstation.Server.Host/Components/Byond/ByondManager.cs
@@ -423,10 +423,10 @@ namespace Tgstation.Server.Host.Components.Byond
 			{
 				if (customVersionStream != null)
 				{
-					int customInstallationNumber = 1;
+					var customInstallationNumber = 1;
 					do
 					{
-						version = new Version(version.Major, version.Minor, customInstallationNumber);
+						version = new Version(version.Major, version.Minor, customInstallationNumber++);
 					}
 					while (installedVersions.ContainsKey(version));
 				}
diff --git a/src/Tgstation.Server.Host/Jobs/JobManager.cs b/src/Tgstation.Server.Host/Jobs/JobManager.cs
index 88828baca2..cac6b4fab3 100644
--- a/src/Tgstation.Server.Host/Jobs/JobManager.cs
+++ b/src/Tgstation.Server.Host/Jobs/JobManager.cs
@@ -54,6 +54,11 @@ namespace Tgstation.Server.Host.Jobs
 		/// </summary>
 		readonly object addCancelLock;
 
+		/// <summary>
+		/// Prevents jobs that are registered after shutdown from activating.
+		/// </summary>
+		volatile bool noMoreJobsShouldStart;
+
 		/// <summary>
 		/// Initializes a new instance of the <see cref="JobManager"/> class.
 		/// </summary>
@@ -122,10 +127,15 @@ namespace Tgstation.Server.Host.Jobs
 					{
 						lock (addCancelLock)
 						{
+							bool jobShouldStart;
 							lock (synchronizationLock)
+							{
 								jobs.Add(job.Id.Value, jobHandler);
+								jobShouldStart = !noMoreJobsShouldStart;
+							}
 
-							jobHandler.Start();
+							if (jobShouldStart)
+								jobHandler.Start();
 						}
 					}
 					catch
@@ -145,8 +155,7 @@ namespace Tgstation.Server.Host.Jobs
 					.AsQueryable()
 					.Where(y => !y.StoppedAt.HasValue)
 					.Select(y => y.Id)
-					.ToListAsync(cancellationToken)
-					;
+					.ToListAsync(cancellationToken);
 				if (badJobIds.Count > 0)
 				{
 					logger.LogTrace("Cleaning {unfinishedJobCount} unfinished jobs...", badJobIds.Count);
@@ -160,19 +169,29 @@ namespace Tgstation.Server.Host.Jobs
 
 					await databaseContext.Save(cancellationToken);
 				}
+
+				noMoreJobsShouldStart = false;
 			});
 
 		/// <inheritdoc />
 		public async Task StopAsync(CancellationToken cancellationToken)
 		{
-			var joinTasks = jobs.Select(x => CancelJob(
-				new Job
+			List<Task<Job>> joinTasks;
+			lock (addCancelLock)
+				lock (synchronizationLock)
 				{
-					Id = x.Key,
-				},
-				null,
-				true,
-				cancellationToken));
+					noMoreJobsShouldStart = true;
+					joinTasks = jobs.Select(x => CancelJob(
+						new Job
+						{
+							Id = x.Key,
+						},
+						null,
+						true,
+						cancellationToken))
+						.ToList();
+				}
+
 			await Task.WhenAll(joinTasks);
 		}
 
diff --git a/tests/Tgstation.Server.Tests/Live/Instance/ByondTest.cs b/tests/Tgstation.Server.Tests/Live/Instance/ByondTest.cs
index 84faa305df..8eac19aaf9 100644
--- a/tests/Tgstation.Server.Tests/Live/Instance/ByondTest.cs
+++ b/tests/Tgstation.Server.Tests/Live/Instance/ByondTest.cs
@@ -59,6 +59,12 @@ namespace Tgstation.Server.Tests.Live.Instance
 
 		async Task TestDeletes(CancellationToken cancellationToken)
 		{
+			var deleteThisOneBecauseItWasntPartOfTheOriginalTest = await byondClient.DeleteVersion(new ByondVersionDeleteRequest
+			{
+				Version = new(TestVersion.Major, TestVersion.Minor, 2)
+			}, cancellationToken);
+			await WaitForJob(deleteThisOneBecauseItWasntPartOfTheOriginalTest, 30, false, null, cancellationToken);
+
 			var nonExistentUninstallResponseTask = Assert.ThrowsExceptionAsync<ConflictException>(() => byondClient.DeleteVersion(
 				new ByondVersionDeleteRequest
 				{
@@ -182,14 +188,27 @@ namespace Tgstation.Server.Tests.Live.Instance
 					UploadCustomZip = true
 				},
 				stableBytesMs,
-				cancellationToken)
-				;
+				cancellationToken);
 
 			Assert.IsNotNull(test.InstallJob);
-			await WaitForJob(test.InstallJob, 60, false, null, cancellationToken);
+			await WaitForJob(test.InstallJob, 30, false, null, cancellationToken);
+
+			// do it again. #1501
+			stableBytesMs.Seek(0, SeekOrigin.Begin);
+			var test2 = await byondClient.SetActiveVersion(
+				new ByondVersionRequest
+				{
+					Version = TestVersion,
+					UploadCustomZip = true
+				},
+				stableBytesMs,
+				cancellationToken);
+
+			Assert.IsNotNull(test2.InstallJob);
+			await WaitForJob(test2.InstallJob, 30, false, null, cancellationToken);
 
 			var newSettings = await byondClient.ActiveVersion(cancellationToken);
-			Assert.AreEqual(new Version(TestVersion.Major, TestVersion.Minor, 1), newSettings.Version);
+			Assert.AreEqual(new Version(TestVersion.Major, TestVersion.Minor, 2), newSettings.Version);
 
 			// test a few switches
 			var installResponse = await byondClient.SetActiveVersion(new ByondVersionRequest
@@ -199,7 +218,7 @@ namespace Tgstation.Server.Tests.Live.Instance
 			Assert.IsNull(installResponse.InstallJob);
 			await ApiAssert.ThrowsException<ApiConflictException>(() => byondClient.SetActiveVersion(new ByondVersionRequest
 			{
-				Version = new Version(TestVersion.Major, TestVersion.Minor, 2)
+				Version = new Version(TestVersion.Major, TestVersion.Minor, 3)
 			}, null, cancellationToken), ErrorCode.ByondNonExistentCustomVersion);
 
 			installResponse = await byondClient.SetActiveVersion(new ByondVersionRequest
diff --git a/tests/Tgstation.Server.Tests/Live/TestLiveServer.cs b/tests/Tgstation.Server.Tests/Live/TestLiveServer.cs
index b3a7596c5f..1ade1e1c5a 100644
--- a/tests/Tgstation.Server.Tests/Live/TestLiveServer.cs
+++ b/tests/Tgstation.Server.Tests/Live/TestLiveServer.cs
@@ -765,6 +765,8 @@ namespace Tgstation.Server.Tests.Live
 					}
 				}
 			}
+			else
+				await internalTask;
 		}
 
 		async Task TestTgsInternal(CancellationToken hardCancellationToken)
@@ -845,7 +847,7 @@ namespace Tgstation.Server.Tests.Live
 						}
 						catch (Exception ex)
 						{
-							System.Console.WriteLine($"[{DateTimeOffset.UtcNow}] TEST ERROR: {ex}");
+							Console.WriteLine($"[{DateTimeOffset.UtcNow}] TEST ERROR: {ex}");
 							serverCts.Cancel();
 							throw;
 						}
@@ -855,8 +857,8 @@ namespace Tgstation.Server.Tests.Live
 					var adminTest = FailFast(new AdministrationTest(adminClient.Administration).Run(cancellationToken));
 					var usersTest = FailFast(new UsersTest(adminClient).Run(cancellationToken));
 					var instanceMangagerTest = new InstanceManagerTest(adminClient, server.Directory);
-					var instancesTest = FailFast(instanceMangagerTest.RunPreTest(cancellationToken));
 					instance = await instanceMangagerTest.CreateTestInstance(cancellationToken);
+					var instancesTest = FailFast(instanceMangagerTest.RunPreTest(cancellationToken));
 					Assert.IsTrue(Directory.Exists(instance.Path));
 					var instanceClient = adminClient.Instances.CreateClient(instance);