[Sticky] [Please read this first] When you post a new topic of bug report...
We have something to tell you how to post a bug report here.
To know exact issue, we need very detailed information about your case.
If you can attach a screenshot of the problem, it will be great!!
At least, you can copy of entire error message and post here, it will be also great!!
Additionally, we need more information like what's your PC environment and circumstance of webserver.
1. OS - Windows? Linux? which version are you using? Windows 10?, Ubuntu?
2. Webserver environment: version of Apache, PHP, MariaDB or MySQL and so on.
3. Hardware- Memory size? The path of Ubuyu installed.
4. What had you tried to do with Ubuyu just before you get the error?
If you add these information with the error information, we could easily analyze and debug your issue.
Thank you for the cooperation in advance & we hope you enjoy Ubuyu!!