I found that when I changed my computer's settings "Size of text, applications, etc." from 150% to 125%, zotero7beta's reading window and the scroll bar on the right hand side for notes, etc., are fully displayed.
Which version of Zotero are you using? Which operating system?
I also observe that the scroll bars of the PDF viewer disappear when reducing the size of the main Zotero window while looking at the PDF viewer, with both left and right panes opened. Observed with Zotero 7.0.0-beta.39+ecba25be0 (64-bit) on Windows 10.
When the Zotero window is in full screen, setting the scaling in Windows to 175%, I can get to this problem (loosing the PDF scroll bars) by squeezing the left and right panes towards the center. But the content of the panes is always correctly displayed to the end, even after increasing the font size in Zotero.
If I reduce the size of the Zotero windows, I have reported the problems in details here.
The only case where I observe that I cannot reach the data at the bottom of the screen with Zotero in full screen is when the plugin PDF Preview is enabled, as shown in this example, where I have pushed the scaling in Windows to 175% and the maximum font size in Zotero.
I have reported some of the problems to tthat plugin GitHub, but they have not been solved yet. So I am not sure what is happening.
I guess that other related plugins may have similar problems. For example, it seems that similar issues have been reported in the PDF Translate plugin by the same author.
@WenXuesec: Do you also observe the problem after disabling all plugins and restarting Zotero?
Tested with Zotero 7.0.0-beta.40+24ae34104 (64-bit) on Windows 10.
I found that after turning off all the Extensions, and then turn them on, the window turned normal. I think it might be the problem of some of the Extensions I used to install. Maybe this could could be the problem.
Upgrade Storage
I also observe that the scroll bars of the PDF viewer disappear when reducing the size of the main Zotero window while looking at the PDF viewer, with both left and right panes opened.
Observed with Zotero 7.0.0-beta.39+ecba25be0 (64-bit) on Windows 10.
If I reduce the size of the Zotero windows, I have reported the problems in details here.
The only case where I observe that I cannot reach the data at the bottom of the screen with Zotero in full screen is when the plugin PDF Preview is enabled, as shown in this example, where I have pushed the scaling in Windows to 175% and the maximum font size in Zotero.
I have reported some of the problems to tthat plugin GitHub, but they have not been solved yet. So I am not sure what is happening.
I guess that other related plugins may have similar problems.
For example, it seems that similar issues have been reported in the PDF Translate plugin by the same author.
@WenXuesec: Do you also observe the problem after disabling all plugins and restarting Zotero?
Tested with Zotero 7.0.0-beta.40+24ae34104 (64-bit) on Windows 10.