​@stanislav.sourek you are not able to double-click on the title? Are you using a trackpad or mouse? What do you mean by a drag line? Can you add a screenshot or video so we can see what is happening?

Hello, I use mouse.
This is block (rectangle container) and I want to Add title, but instead of This nothing happen
or I start to create a line because the arrow.

Hi ​@stanislav.sourek , 

Thanks for posting in the Lucid Community! I believe you have identified a bug, and I have reported this to our development team. I apologize for any disruption this may cause, and I will update this thread with any new information about a fix.

As a workaround in the meantime, you can drag out a text box to add a title to your container. 

Please follow along on this thread for updates, and post any additional questions or concerns below. 

Please help! I wish to wrap several Lucidchart objects in a container and add a title to the container. Clicking on containers reveals an "add title" caption that is grayed out. I can sometimes type in a title and sometimes not, even though I do EXACTLY THE SAME THING each time. What's the secret?

Hi ​@DanTomaselli, thank you for posting in the community! It looks like you are experiencing the same bug reported in this post. I’ve gone ahead and merged your post into this one.

As mentioned by my colleague Michelle S, the current workaround is to use a text box shape to add a title. Please follow this thread for updates and let us know if you have any questions. 
 

Good morning,

For those experiencing this issue, could you add what browser and operating system (mac, windows, etc) that you’re using? I want to make sure that is captured in the bug report.