[נפתר] Real3D Flipbook & PDF Viewer not working on default language

Background of the issue:
I am trying to: Real3D Flipbook & PDF Viewer plugin workign right on English pages, but when i swithc on Germany (default) it stop working and on console i have an error. already try to switch off/on plugins and default theme. when i using default theme all working like it should and pdf shoing on both languages. Link to a page where the issue can be seen: קישור נסתר. I expected to see: opened pdf as on english page קישור נסתר

Symptoms:
Instead, I got: bugged pdf, not working plugin and error on console. jQuery.Deferred exception: Cannot read properties of undefined (reading 'options') TypeError: Cannot read properties of undefined (reading 'options') at new FLIPBOOK.Main (קישור נסתר) at t.fn.flipBook (קישור נסתר) at HTMLDivElement. (קישור נסתר) at Function.each (קישור נסתר) at HTMLDocument. (קישור נסתר) at mightThrow (קישור נסתר) at process (קישור נסתר) undefined jQuery.Deferred.exceptionHook @ app.js?id=bd697d72bb94dfc380f8:8470 process @ app.js?id=bd697d72bb94dfc380f8:8258 setTimeout (async) (anonymous) @ app.js?id=bd697d72bb94dfc380f8:8292 fire @ app.js?id=bd697d72bb94dfc380f8:7920 fireWith @ app.js?id=bd697d72bb94dfc380f8:8050 fire @ app.js?id=bd697d72bb94dfc380f8:8058 fire @ app.js?id=bd697d72bb94dfc380f8:7920 fireWith @ app.js?id=bd697d72bb94dfc380f8:8050 ready @ app.js?id=bd697d72bb94dfc380f8:8530 completed @ app.js?id=bd697d72bb94dfc380f8:8540 app.js?id=bd697d72bb94dfc380f8:8479 Uncaught TypeError: Cannot read properties of undefined (reading 'options') at new FLIPBOOK.Main (flipbook.min.js?ver=4.6.5:1:11064) at t.fn.flipBook (flipbook.min.js?ver=4.6.5:1:103) at HTMLDivElement. (embed.js?ver=4.6.5:1:4607) at Function.each (app.js?id=bd697d72bb94dfc380f8:4805:19) at HTMLDocument. (embed.js?ver=4.6.5:1:85) at mightThrow (app.js?id=bd697d72bb94dfc380f8:8186:29) at process (app.js?id=bd697d72bb94dfc380f8:8254:12)

Questions:
Why does the Real3D Flipbook & PDF Viewer plugin stop working on the default German language page?
What could be causing the 'Cannot read properties of undefined (reading 'options')' error in the console?
Why does the plugin work correctly with the default theme but not with the current theme?