Qt Designer preview not working

[LT-K101]

Hi
Just this morning I tried previewing my design I created with Qt Designer but after few second Qt designer exits but I can preview other .ui files. I don't know what is happening, I need help please. Thanks in advance.

[jsulm]

@LT-K101 Start designer from a terminal and see whether it outputs any errors

[LT-K101]

@jsulm When I start designer from terminal , I get this prompt message in the image below.

[jsulm]

@LT-K101 And what happens when you continue (press yes or no)?

[LT-K101]

@jsulm When I click on yes ,it enlarges the parent window and the right edge GUI is grayed out when i scroll to the right as shown below.