fix(admin-ui):blanck page while adding assets

[manojs1978]

Describe the bug
blanck page while adding assets

To Reproduce
Steps to reproduce the behavior:

1. install 5.1.4.nightly
2. goto asset
3. add png file
4. See error

Expected behavior
should not get blank page

Screenshots
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Desktop (please complete the following information):

• OS: suse 15
• Browser [e.g. chrome, safari]
• Version sp 5
• flex 5.1.4.nightly
• DB pgsql

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.