In Partner Login, on viewing Auto Enroll Benifit screen, Server error occured on View changes button. PFA Error log & screen shot

Exception : Invalid length for a Base-64 char array or string.
App Error Log : -
Employee ID : 0
Action Name : ViewReport
Model : System.Web.Mvc.HandleErrorInfo
Controller : Common
Web Error Log : at System.Convert.FromBase64_Decode(Char* startInputPtr, Int32 inputLength, Byte*

startDestPtr, Int32 destLength)
at System.Convert.FromBase64CharPtr(Char* inputPtr, Int32 inputLength)
at System.Convert.FromBase64String(String s)
at EBS.AESCryptography.DecryptString(String base64StringToDecrypt, String passphrase)
at WORKTERRA.SharedFunctionWebTier.DecryptString(String Input, Boolean EncodeURL)
at WORKTERRA.Shared.Controllers.CommonController.DecryptReportParameters(String& ReportName,

String& ReportType, String& ReportExportType, String& DummyCompanyID)
at WORKTERRA.Shared.Controllers.CommonController.ViewReport(String ReportName, String ReportType,

String ReportExportType, String DummyCompanyID)
at lambda_method(Closure , ControllerBase , Object[] )
at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext,

IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext,

ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.<>c_DisplayClass13.b_10()
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter,

ActionExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext

controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String

actionName)