In 25R2 Acumatica is pushing everyone toward the “Modern UI” (HTML/TS) customization path and, as part of that change, the old in-product ASPX Editor is effectively no longer available.
Solved
Unable to edit the ASPX of an existing screen in 25R2
Best answer by Siddu
here i find Reference :
Customized Acumatica Screens With Modern UI in 25R2 | Community
I hope it helps!
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