I'm in QGIS layouts trying to make a custom grid coordinate format but get the error:

No feature was found on this layer to evaluate the expression.

This error does not appear if I have a single substr() function but when I add a second it errors.

concat(substr(@grid_number, -5, 2),
       substr(@grid_number, -3)

enter image description here

  • OP should add information about what is the aim of the expression and what the variable @grid_number represents.
    – Babel
    Sep 10, 2021 at 20:13
  • @Babel @grid_number is a built in expression in printlayout representing the current lat/lon value of the added grid.
    – MrXsquared
    Sep 10, 2021 at 20:26
  • @MrXsquared - OK, I see, a context variable.
    – Babel
    Sep 10, 2021 at 20:31

1 Answer 1


Change your double quotes of "," into single quotes ',', since it is not related to a fieldname but is meant to represent a string value:

concat(substr(@grid_number, -5, 2),
       substr(@grid_number, -3)

The error No feature was found on this layer to evaluate the expression. is caused by QGIS trying to lookup for a field named , but there is no feature which this expression is evaluated against and therefore also no fieldname named like that.

  • Thank you. No matter the programming language I always get confused about double and single quotes. Wish QGIS had better docs for their language.
    – jake9wi
    Sep 12, 2021 at 23:44

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