diff --git a/openbis-ipad/BisKit/Classes/CISDOBConnection.m b/openbis-ipad/BisKit/Classes/CISDOBConnection.m
index f1d9656f6375e88be8a9025101fe03df68bd92a3..a7a2c9c07e02bea78b2aa4302b19f0f4d57eae24 100644
--- a/openbis-ipad/BisKit/Classes/CISDOBConnection.m
+++ b/openbis-ipad/BisKit/Classes/CISDOBConnection.m
@@ -190,9 +190,28 @@ NSString *const CISDOBConnectionErrorDomain = @"CISDOBConnectionErrorDomain";
     return self;
 }
 
+- (void)replaceSessionToken:(NSString *)oldSessionToken with:(NSString *)sessionToken
+{
+    NSArray *oldParams = self.params;
+    if ([[oldParams objectAtIndex: 0] isEqualToString: oldSessionToken]) {
+        NSMutableArray *params = [oldParams mutableCopy];
+        [params replaceObjectAtIndex: 0 withObject: sessionToken];
+        self.params = params;
+    }
+}
+
 - (void)start
 {
     [_connection executeCall: self];
 }
 
+@end
+
+@implementation CISDOBConnection (CISDOBConnectionTesting)
+
+- (void)setSessionTokenForTesting:(NSString *)bogusSessionToken
+{
+    _sessionToken = bogusSessionToken;
+}
+
 @end
\ No newline at end of file
diff --git a/openbis-ipad/BisKit/Classes/CISDOBConnectionInternal.h b/openbis-ipad/BisKit/Classes/CISDOBConnectionInternal.h
index a4c93f57ce50e7117eda3d0b38e0e034ecfa6e95..ccb54157620694d84742ce235870561a658222e7 100644
--- a/openbis-ipad/BisKit/Classes/CISDOBConnectionInternal.h
+++ b/openbis-ipad/BisKit/Classes/CISDOBConnectionInternal.h
@@ -38,4 +38,16 @@
 // Initialization
 - (id)initWithConnection:(CISDOBConnection *)aConnection method:(NSString *)aString params:(NSArray *)anArray;
 
+// Actions
+- (void)replaceSessionToken:(NSString *)oldSessionToken with:(NSString *)sessionToken;
+@end
+
+
+/**
+ *  \brief An interface with methods that support testing. These methods are used to get the connection into error states. There should be no need to use them outside of testing.
+ */
+@interface CISDOBConnection (CISDOBConnectionTesting)
+
+- (void)setSessionTokenForTesting:(NSString *)bogusSessionToken;
+
 @end
diff --git a/openbis-ipad/BisKit/Classes/CISDOBIpadService.m b/openbis-ipad/BisKit/Classes/CISDOBIpadService.m
index 74751bead23eb6ca448e3e1fbe9cf09c1bf0e9df..f48755e80f8dd03d13b0243b2b750cd626eead87 100644
--- a/openbis-ipad/BisKit/Classes/CISDOBIpadService.m
+++ b/openbis-ipad/BisKit/Classes/CISDOBIpadService.m
@@ -25,6 +25,7 @@
 #import "CISDOBIpadServiceInternal.h"
 #import "CISDOBConnection.h"
 #import "CISDOBAsyncCall.h"
+#import "CISDOBConnectionInternal.h"
 
 NSString *const CISDOBIpadServiceErrorDomain = @"CISDOBIpadServiceErrorDomain";
 
@@ -241,6 +242,12 @@ NSString *const CISDOBIpadServiceErrorDomain = @"CISDOBIpadServiceErrorDomain";
     return self;
 }
 
+- (void)replaceSessionToken:(NSString *)oldSessionToken with:(NSString *)sessionToken
+{
+    CISDOBConnectionCall *connectionCall = (CISDOBConnectionCall *) _connectionCall;
+    [connectionCall replaceSessionToken: oldSessionToken with: sessionToken];
+}
+
 - (void)start
 {
     _connectionCall.timeoutInterval = self.timeoutInterval;
diff --git a/openbis-ipad/BisKit/Classes/CISDOBIpadServiceInternal.h b/openbis-ipad/BisKit/Classes/CISDOBIpadServiceInternal.h
index dd3afa420be974fdbacd777faa48a9a114216c34..4c4d9d38d37ee1f90170b75a72fe25155eb0dbde 100644
--- a/openbis-ipad/BisKit/Classes/CISDOBIpadServiceInternal.h
+++ b/openbis-ipad/BisKit/Classes/CISDOBIpadServiceInternal.h
@@ -35,5 +35,8 @@
 // Initialization
 - (id)initWithService:(CISDOBIpadService *)service connectionCall:(CISDOBAsyncCall *)call;
 
+// Actions
+- (void)replaceSessionToken:(NSString *)oldSessionToken with:(NSString *)sessionToken;
+
 @end
 
diff --git a/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManager.h b/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManager.h
index fbb109ae603338c5db51d5fc813781de524670e7..42a24b5a48eb4129f073a1279fcdfb258ec8f829 100644
--- a/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManager.h
+++ b/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManager.h
@@ -74,13 +74,15 @@ typedef void (^MocSaveBlock)(CISDOBIpadServiceManager *serviceManager, NSArray *
 @interface CISDOBIpadServiceManager : NSObject
 
 @property (readonly) NSURL *openbisUrl;
-@property (readonly, strong) CISDOBIpadService *service;
-@property (readonly, strong) NSURL *storeUrl;
-@property (readonly, strong) NSManagedObjectContext *managedObjectContext;
-@property (readonly, strong) NSManagedObjectModel *managedObjectModel;
-@property (readonly, strong) NSPersistentStoreCoordinator *persistentStoreCoordinator;
-@property (readonly, strong) NSEntityDescription *ipadEntityDescription;
-@property (readonly, strong) NSOperationQueue *queue;
+@property (readonly) CISDOBIpadService *service;
+@property (readonly) NSString *username;
+@property (readonly) NSString *password;
+@property (readonly) NSURL *storeUrl;
+@property (readonly) NSManagedObjectContext *managedObjectContext;
+@property (readonly) NSManagedObjectModel *managedObjectModel;
+@property (readonly) NSPersistentStoreCoordinator *persistentStoreCoordinator;
+@property (readonly) NSEntityDescription *ipadEntityDescription;
+@property (readonly) NSOperationQueue *queue;
 @property (readonly) NSString *sessionToken;
 @property (nonatomic, getter=isOnline) BOOL online;
 
diff --git a/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManager.m b/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManager.m
index 60bb58a785b76192e5c927f76884d3b9182ab530..9d615759f060ad557291d964f5c7662bc2fa7a00 100644
--- a/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManager.m
+++ b/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManager.m
@@ -25,6 +25,7 @@
 #import "CISDOBIpadServiceManager.h"
 #import "CISDOBIpadServiceManagerInternal.h"
 #import "CISDOBIpadService.h"
+#import "CISDOBIpadServiceInternal.h"
 #import "CISDOBIpadEntity.h"
 #import "CISDOBConnection.h"
 
@@ -165,6 +166,41 @@ static NSManagedObjectContext* GetMainThreadManagedObjectContext(NSURL* storeUrl
     [_queue addOperationWithBlock: syncBlock];
 }
 
+- (BOOL)shouldRetryCall:(CISDOBIpadServiceManagerCall *)managerCall onError:(NSError *)error
+{
+    // We can retry JsonRpc errors caused by invalid session tokens
+    if (![CISOBJsonRpcErrorDomain isEqualToString: error.domain]) return false;
+
+    NSDictionary *jsonErrorObject = [[error userInfo] objectForKey: CISOBJsonRpcErrorObjectKey];
+    if (!jsonErrorObject) return false;
+    NSDictionary *errorData = [jsonErrorObject objectForKey: @"data"];
+    if (!errorData) return false;
+    NSString *exceptionTypeName = [errorData objectForKey: @"exceptionTypeName"];
+    if (!exceptionTypeName) return false;
+    if (![@"ch.systemsx.cisd.common.exceptions.InvalidSessionException" isEqualToString: exceptionTypeName]) return false;
+    
+    return managerCall.retryCount < 1;
+}
+
+- (void)loginAndRetryCall:(CISDOBIpadServiceManagerCall *)managerCall
+{
+    if (!_username || !_password) return;
+    
+    NSString *oldSessionToken = self.service.connection.sessionToken;
+    
+    // Login and then retry the call
+    managerCall.retryCount =  managerCall.retryCount + 1;
+    CISDOBAsyncCall *call = [self.service.connection loginUser: _username password: _password];
+    call.success = ^(id result) {
+        // Fix the session token
+        CISDOBIpadServiceCall *serviceCall = (CISDOBIpadServiceCall *)managerCall.serviceCall;
+        [serviceCall replaceSessionToken: oldSessionToken with: result];
+        [managerCall start];
+    };
+    call.fail = ^(NSError *error) { [managerCall notifyFailure: error]; };
+    [call start];
+}
+
 - (CISDOBIpadServiceManagerCall *)managerCallWrappingServiceCall:(CISDOBAsyncCall *)serviceCall pruning:(BOOL)prune
 {
     CISDOBIpadServiceManagerCall *managerCall = [[CISDOBIpadServiceManagerCall alloc] initWithServiceManager: self serviceCall: serviceCall];
@@ -178,6 +214,11 @@ static NSManagedObjectContext* GetMainThreadManagedObjectContext(NSURL* storeUrl
     };    
     
     serviceCall.fail = ^(NSError *error) {
+        if ([weakSelf shouldRetryCall: managerCall onError: error]) {
+            [self loginAndRetryCall: managerCall];
+            return;
+        }
+        
         // Check the error -- the server could be unavailable
         if ([NSURLErrorDomain isEqualToString: error.domain] && -1004 == error.code) {
             // "Could not connect to the server"
@@ -197,6 +238,9 @@ static NSManagedObjectContext* GetMainThreadManagedObjectContext(NSURL* storeUrl
 - (CISDOBAsyncCall *)loginUser:(NSString *)user password:(NSString *)password
 {
     CISDOBAsyncCall *call = [self.service loginUser: user password: password];
+    // Remember the username and password so we can reauthenticate if necessary
+    _username = user;
+    _password = password;
     CISDOBIpadServiceManagerCall *managerCall = [self managerCallWrappingServiceCall: call pruning: NO];
     call.success = ^(id result) { [managerCall notifySuccess: result]; };
     managerCall.willCallNotificationName = CISDOBIpadServiceWillLoginNotification;
@@ -341,6 +385,7 @@ static NSManagedObjectContext* GetMainThreadManagedObjectContext(NSURL* storeUrl
     _serviceManager = serviceManager;
     _serviceCall = call;
     self.timeoutInterval = call.timeoutInterval;
+    self.retryCount = 0;
     
     return self;
 }
diff --git a/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManagerInternal.h b/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManagerInternal.h
index 0ad4b6fb255ba0e72ff7cd572005a7050ecb2beb..d70cd819085ee2d65cdb2c2ad7082ff756669997 100644
--- a/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManagerInternal.h
+++ b/openbis-ipad/BisKit/Classes/CISDOBIpadServiceManagerInternal.h
@@ -30,6 +30,7 @@
 
 @property(weak, nonatomic) CISDOBIpadServiceManager *serviceManager;
 @property(strong, nonatomic) CISDOBAsyncCall *serviceCall;
+@property(nonatomic) NSUInteger retryCount;     //<! How many times has this call been retried
 
 @property(copy, nonatomic) NSString *willCallNotificationName;  //<! The notification called before the call takes place, may be nil
 @property(copy, nonatomic) NSString *didCallNotificationName;   //<! The notification called after the call has completed, may be nil
diff --git a/openbis-ipad/BisKit/Tests/CISDOBIpadServiceManagerTest.m b/openbis-ipad/BisKit/Tests/CISDOBIpadServiceManagerTest.m
index e2456679f6e8b2307094c5d3d4e3eccf348da396..5cf662506220e8051c26f4c66108c942bef09f20 100644
--- a/openbis-ipad/BisKit/Tests/CISDOBIpadServiceManagerTest.m
+++ b/openbis-ipad/BisKit/Tests/CISDOBIpadServiceManagerTest.m
@@ -316,6 +316,22 @@
     [self checkFindingChildren];
 }
 
+- (void)testInvalidSessionToken
+{
+    [self performLogin];
+    [self performRootLevelCall];
+    
+    // Switch the session token
+    [self.serviceManager.service.connection setSessionTokenForTesting: @"junk"];
+
+    // Get drill information on some entity
+    NSArray *entitiesWithChildren = [self entitiesWithChildren];
+    STAssertTrue([entitiesWithChildren count] > 0, @"There should be some entities with children");    
+    CISDOBIpadEntity *drillEntity = [entitiesWithChildren objectAtIndex: 0];
+    [self performDrill: drillEntity];
+    NSLog(@"Error %@", _callError);
+}
+
 - (void)retrieveRootLevelEntitiesSimulatingRemovalOfEntity:(CISDOBIpadEntity *)entityToRemove
 {
     // Make a root level call, but do have some entities removed from the list
diff --git a/openbis-ipad/Research/BisMac.xcodeproj/project.xcworkspace/xcuserdata/cramakri.xcuserdatad/UserInterfaceState.xcuserstate b/openbis-ipad/Research/BisMac.xcodeproj/project.xcworkspace/xcuserdata/cramakri.xcuserdatad/UserInterfaceState.xcuserstate
index f59b530d600f7e1e08f5cbfda494d15483b616f0..12a44a733ed5af09622e4bc5083a90a5d8fbb7fe 100644
Binary files a/openbis-ipad/Research/BisMac.xcodeproj/project.xcworkspace/xcuserdata/cramakri.xcuserdatad/UserInterfaceState.xcuserstate and b/openbis-ipad/Research/BisMac.xcodeproj/project.xcworkspace/xcuserdata/cramakri.xcuserdatad/UserInterfaceState.xcuserstate differ
diff --git a/openbis-ipad/openBIS/openBIS.xcodeproj/project.xcworkspace/xcuserdata/cramakri.xcuserdatad/UserInterfaceState.xcuserstate b/openbis-ipad/openBIS/openBIS.xcodeproj/project.xcworkspace/xcuserdata/cramakri.xcuserdatad/UserInterfaceState.xcuserstate
index 0d34586ff21721cfe189aca25403fd8a86d998b5..e6393a3e969948b1bd39db7e9f0a8408ab761ad1 100644
Binary files a/openbis-ipad/openBIS/openBIS.xcodeproj/project.xcworkspace/xcuserdata/cramakri.xcuserdatad/UserInterfaceState.xcuserstate and b/openbis-ipad/openBIS/openBIS.xcodeproj/project.xcworkspace/xcuserdata/cramakri.xcuserdatad/UserInterfaceState.xcuserstate differ