A Truncation Occurred During Evaluation Of The Expression

First of all, I get the following error message for one of my packages which uses user variables:

SSIS package "UsageAnalysis.dtsx" starting.
Information: 0x4004300A at Perform xmlState Shredding, DTS.Pipeline: Validation phase is beginning.
Information: 0x4004300A at Update Analysis Table, DTS.Pipeline: Validation phase is beginning.
Information: 0x4004300A at Update Analysis Table, DTS.Pipeline: Validation phase is beginning.
Error: 0xC001700E at UsageAnalysis: A truncation occurred during evaluation of the expression.
Error: 0xC0019004 at UsageAnalysis: The expression for variable "GetAnalysisData" failed evaluation. There was an error in the expression.
Error: 0xC02020E9 at Update Analysis Table, UsageAnalysis Source [1]: Accessing variable "User::GetAnalysisData" failed with error code 0xC001700E.
Error: 0xC0024107 at Update Analysis Table: There were errors during task validation.
Warning: 0x80019002 at Usage Analysis Process: SSIS Warning Code DTS_W_MAXIMUMERRORCOUNTREACHED. The Execution method succeeded, but the number of errors raised (5) reached the maximum allowed (1); resulting in failure. This occurs when the number of errors reaches the number specified in MaximumErrorCount. Change the MaximumErrorCount or fix the errors.
SSIS package "UsageAnalysis.dtsx" finished: Failure.




Now my package has the following variables:
GetMaxUsageID: scope package level, type string, statement SELECT MAX(UsageID) AS MaxUsageID FROM XX.XXX
MaxUsageID: scope package level, type int32, default value 0, value get assigned from the following statement executed from sql task that runs GetMaxUsageID variable as above
GetAnalysisData: scope package level, type string, Evaluate as Expression
"SELECT * FROM dbo.UsageAnalysis WHERE UsageID > " + (DT_STR, 8, 1252) @[User::MaxUsageID]

The package has worked fine until MaxUsageID value reached to 10,00,000 and since then I have been getting above mentioned error message. The problematic step is related to Data Flow task where I use GetAnalysisData. I have tried replacing user variable with literal as follows

"SELECT * FROM dbo.UsageAnalysis WHERE UsageID > 1000000"

the error message stays the same. Please note that package has worked fine before and it still works ok if I don't use user variables. Obviously, some of you would see eliminating user variables as workaround but I would appreciate if cause of that error message could be investigated.

Thanks,
Asaf