# Troubleshooting

- [Relation ‘experiment\_condition’ already exists](/upgrade-documentation/developer-guide/faq-error-resolution/relation-experiment_condition-already-exists.md)
- [User not found. Authorization error](/upgrade-documentation/developer-guide/faq-error-resolution/user-not-found.-authorization-error.md)
- [Token is not present in the request header](/upgrade-documentation/developer-guide/faq-error-resolution/token-is-not-present-in-the-request-header.md)
- [nodemon exits without explanation](/upgrade-documentation/developer-guide/faq-error-resolution/nodemon-exits-without-explanation.md)
- [Unable to find New Relic module configuration](/upgrade-documentation/developer-guide/faq-error-resolution/unable-to-find-new-relic-module-configuration.md)
- [No email received for export data](/upgrade-documentation/developer-guide/faq-error-resolution/no-email-received-for-export-data.md)
- [Opening a new tab in UpGrade prompts for re-authorization](/upgrade-documentation/developer-guide/faq-error-resolution/opening-a-new-tab-in-upgrade-prompts-for-re-authorization.md)
- [Error: Cannot find module 'upgrade\_types' (or a type from 'upgrade\_types' does not exist)](/upgrade-documentation/developer-guide/faq-error-resolution/error-cannot-find-module-upgrade_types-or-a-type-from-upgrade_types-does-not-exist.md)