Installing Invoiceplane in a subfolder - "404 Error"

Support
5

Thanks. The log is not very helpful:

ERROR - 2020-04-25 10:40:08 --> 404 Page Not Found: /index
DEBUG - 2020-04-25 10:40:46 --> UTF-8 Support Enabled
DEBUG - 2020-04-25 10:40:46 --> Global POST, GET and COOKIE data sanitized
ERROR - 2020-04-25 10:40:46 --> 404 Page Not Found: /index
DEBUG - 2020-04-25 10:40:48 --> UTF-8 Support Enabled
DEBUG - 2020-04-25 10:40:48 --> Global POST, GET and COOKIE data sanitized
ERROR - 2020-04-25 10:40:48 --> 404 Page Not Found: /index