I assume you are running NPrinting 16.X.X.
Now - Variable.
Could you please look at variable in your source document - this will be your qvw file. Find your variable there and look how it is generated. Does it return value?
Maybe share how this variable is calculated.
Is it in:
- script or in front-end
- Is it SET, LET
- maybe value gets changed by trigger
- Is it an expression?
Please let us know
I believe NPrinting has a variable in metadata. When did you refresh metadata last time? It may be gone from your source document or not calculated there.
I am not sure what possibly could happened to your variable.
Maybe have a look at this document: How to Include Dynamic Elements in NPrinting E-mail and see whether you are using recipient variable or global variable in NPrinting.
How do you trigger your reports and how they are distributed? Is this a Server generated process which sudenly stopped working or you trigger it manually?