Issue Summary

In Confluence v7.19.5 and v7.19.6, the user-created templates fail to render/populate the field with underscore, dash, and colon characters. In the latest version of Confluence(v8.1.1 as of now), the issue is reproducible. 

Unlike the above versions, in Confluence v7.19.2 and 7.19.4 allows using the field with underscore, dash, and colon characters.

Update: The issue is reproducible not only for variable names but also list variable contents.

Steps to Reproduce

1. Navigate to Space Tools > Content Tools > Templates > User Created Templates
2. Click Create New Template button
3. Choose the Insert Templates Item option and add New Variable
4. Name the variable as var
5. Add another variable and name it var_underscore
6. Add another variable and name it var-dash
7. Add another variable and name it var:colon
8. Save 
9. Create a new page using this template

Expected Results

All fields should be rendered/populated while creating a page using the template.

Actual Results

The fields with underscore, dash, and colon characters failed. 

Workaround

Avoid using underscore, dash, colon, and Japanese characters with the field names.