Strange error attempting to save a record with a blob jpg...

Strange error attempting to save a record with a blob jpg...

I have developed a VCL application in Delphi, using RAD Studio 12 Version 29.0.51961.7529 (Version 12.1 basically) with a target platform Windows64. It uses Devart MySQLDAC 12.2.1 For RADStudio 12 for database 
My customer has just emailed to say they have experienced a problem with inserting pictures via an app i developed for them. The image can be loaded from file into the TImage component and visually displayed, but when they hit they get the following error:

EAssertationFailed error raised with message :
Assertion failure (D:\Jenkins\workspace\MyDAC\Delphi\Dac\Common\Source\MemDS.pas line 2504)

As the developer, I have no idea where this path is, it doesn't exist on the customer computer, nor does it exist on my development computer!

Any help narrowing the error down?

Any ideas