Before opening an issue:

• Check that you have installed the latest version of qgis2web
• Search among the issues if a similar report already exists and if you can find your solution
• Simplify your project with simple layer names, simple field names, simple symbols (Avoid apostrophe, double quotes, parentheses, accents..)
• Attach an example of your project so that we can reproduce the issue
• If you can't attach an example project, attach screenshots

For the experts:

• Paste qgis2web or QGIS Python console errors
• Paste browser console errors