This warning in the Taxonomy Check is triggered due to the presence in the xHTML check of other warnings. This warning only summarizes the presence of the others, which can be triggered by validation errors.
Fixing the validation errors (red) first and then the remaining warnings in the xHTML Check will solve this warning as well.
If your report produces the warning "formula:assertionunsatisfied" because there is a missing element, simply adding the missing element in question will also remove the "ESEF.2.7.1 targetXBRLDocumentWithFormulaWarnings".
Because the violation in question is related to a warning, it is a non-blocking error, which means you do not necessarily need to correct it.