An HMI import dialog that opens with its Browse, Import, Cancel and Help buttons missing is drawn for 96 DPI on a Windows desktop scaled to 120 DPI, 25 percent larger. Drag the dialog's corner once to rule out plain clipping, then set display scaling back to 96 DPI, start the software again and test. Antivirus was already ruled out; reinstalling is the last check.
An HMI import dialog that opens with its Browse, Import, Cancel and Help buttons missing is a display-settings fault, not a broken install and almost never antivirus. The dialog is laid out for Windows' standard 96 DPI while the desktop runs large size, 120 DPI, so every control draws 25 percent lower and the button row drops below the window's bottom edge. Plenty of HMI workstations still run Windows XP or Windows 7, where this switch is live, and the fault has been reproduced at large size (120 DPI) on Windows XP while the same comparison left Windows 7 clean. Give the window one 30-second corner drag, then change the DPI setting. Reinstall only if both display checks fail.
First test: drag the corner once
Pull the bottom-right corner of the import dialog down and to the right, making it taller and wider. If the four buttons appear, the window simply opened smaller than its content: finish the import with the controls now visible, and still do the DPI check below, because a desktop left at 120 DPI clips the same row again at the next launch.
If nothing appears, stop dragging. In the reproduced fault the window was enlarged and the buttons stayed gone, and that result is the useful one: the content sits past the window edge by more than a quick resize recovers. That gap has a number, worked out in the example below, and the cure is the DPI setting.
A dialog with no resize handle skips this test entirely. Go straight to the display settings.
What each symptom points to
| What you see | What it points to | What to do next |
|---|---|---|
| Only the library-import dialog loses buttons; the other import and export windows open normally | That one dialog is drawn for 96 DPI on a desktop scaled to 120 DPI | One corner drag, then change the DPI setting |
| Buttons appear after you drag the corner | Plain clipping: the window opened smaller than its content | Finish the import, then set the DPI back to 96 so the fix holds |
| Buttons stay missing after the corner drag | The 25 percent scaling gap, too large for a quick resize to recover | Change the DPI setting |
| Buttons are there but their labels are cut off even at 96 DPI | A legacy Windows font fault, separate from scaling | See fixing dialogs clipped by legacy Windows fonts |
| Every window on the desktop draws wrong: text oversized, windows wider than the monitor | A resolution or graphics driver problem, not one dialog | Check the resolution and the driver before touching the software |
| The import fails after you select a file | A file or library problem, not layout | See fixing a bitmap import that shows a red X |
The split saves the afternoon. A fault that lives in one window is scaling and layout, fixed in two minutes at the display settings; a fault that spans every window lives in the resolution, the driver or the monitor, and no reinstall will move it.
Change the DPI setting
- Write down what the PC shows now: the Windows version, the screen resolution and the current DPI or zoom setting. If the change has to be undone, you will want the original numbers.
- Open Control Panel > Display, where the DPI or zoom control lives. On Windows XP the choice is between normal size, 96 DPI, and large size, 120 DPI; take normal size. On Windows 7 and later the same control is a percentage: 100 percent is the standard 96 DPI, and 125 percent is the same 120 DPI that reproduces the fault.
- Apply the change and let Windows restart the session if it asks. Older Windows wants a restart before the new DPI reaches every program.
- Start the HMI software and open the library-import dialog. Browse, Import, Cancel and Help should now sit inside the window with room to spare.
- Run one real import end to end, close the software, start it again and open the dialog once more. A fix that survives a relaunch is the one to keep; write the 96 DPI setting into the workstation's maintenance notes so the next tune-up does not restore large size.
The same setting explains a cousin fault: Windows DPI produces an HMI editor that draws objects but no screen text, so when a workstation misdraws anything at large size, check 96 DPI before you touch the software. The pattern is not unique to one package either; off-screen OK and Cancel buttons in legacy HMI software is a documented instance of the same dialog-layout fault.
Example: what 120 DPI does to a 96 DPI dialog
A dialog drawn for 96 DPI opens on a desktop set to 120 DPI, and Windows applies a scale factor of 120 / 96 = 1.25. Everything the dialog draws grows 25 percent in each direction; the window itself still opens at its designed size.
Take an illustrative dialog 320 pixels tall, with its button row in the last 40 pixels, from y = 280 to y = 320. At 120 DPI the row draws from 280 × 1.25 = 350 to 320 × 1.25 = 400. The window opens 320 pixels tall, so the strip from y = 320 to y = 400, 80 pixels of content (400 - 320 = 80), sits below the window's bottom edge. That strip holds exactly the controls you lost: Browse, Import, Cancel and Help.
This is why the corner drag came up empty in the reproduced fault. Recovering by mouse alone means growing the window from 320 to more than 400 pixels, 25 percent past the size it opens at, and a quick pull rarely gets there. Setting the DPI back to 96 removes the 1.25 multiplier and puts the row back at y = 280 to 320, inside the window.
The heights and row positions here are illustrative; a screenshot of your own dialog gives you the real numbers. The multiplier is the part that generalizes: 120 DPI is 1.25 times 96 DPI, so every fixed 96 DPI layout on a 120 DPI desktop spills past a fixed window by that factor.
Antivirus and reinstall come last
Antivirus was switched off in the fault as first reported and the buttons stayed missing, and the symptom pattern agrees with that result. Antivirus interference looks like a file that will not open, a copy that fails or a program that will not start; here the dialog opened and the other import and export windows worked normally. One window with hidden controls is a layout problem, so keep antivirus out of the first hour, and if you do test without it, switch protection back on immediately afterwards.
Reinstall is the last check that can help, and only after the corner drag and the 96 DPI change have both failed. One cycle is enough:
- Record the software edition, the Windows version, the resolution and the DPI setting.
- Close the software, uninstall it through the normal Windows process and reboot.
- Install it again from the software maker's own installer or its authorized distributor, from nowhere else.
- Open the project and test the import dialog before changing anything else on the PC.
If the buttons are still missing after the resize, the DPI change and one reinstall, stop cycling settings. Pass on the four recorded facts, plus one observation: whether the other import and export windows still work.
When to stop, and what to hand over
The decision, case by case. Buttons missing on one import dialog: fix at 96 DPI and keep the workstation there. Buttons visible but labels clipped even at 96 DPI: the fonts fault from the table, fixed in the font settings. Every window drawn wrong: resolution and graphics driver. Import failing after the file is chosen: the file itself. Large size stays on the menu for any operator who needs it to read the interface, and the cost is repeating the corner drag at every import.
Recommendation: keep any PC that runs legacy HMI software at 96 DPI, 100 percent on Windows 7 and later, unless an operator needs large size for accessibility; when the import dialog loses its buttons, do one corner drag, set the DPI back to 96, start the software again and run a real import before you touch antivirus or reinstall anything.
Questions
Windows 10 or 11 runs the HMI software: is the DPI fix the same?
Set the desktop scaling to 100 percent first, then use the per-program override if the import dialog still clips: right-click the HMI program's icon, open Properties, open the Compatibility tab and click the high-DPI settings button. The override tells Windows to handle that program's scaling itself instead of leaving it to the desktop setting. Start the software again and test the import dialog; the same override is where a legacy program that draws tiny at high resolutions gets fixed too.
Why does only the library-import dialog lose its buttons while other windows are fine?
The split is the clue. A fault that lives in one window belongs to that window's layout and how it handles DPI, and 96 DPI fixes it. The same missing controls in every window would point somewhere else entirely: the screen resolution, the graphics driver or the monitor itself. Keep the two cases apart, because the first is a two-minute settings change and the second has nothing to do with the HMI software.
Can I stay at 120 DPI and still use the import dialog?
Yes, by resizing. On a 120 DPI desktop the dialog needs a window 25 percent taller than the size it opens at, so drag the corner until Browse, Import, Cancel and Help are all visible and finish the import that way. You repeat the drag at every launch, which is why 96 DPI stays the practical setting for a workstation that imports libraries often; large size remains worth keeping only where an operator needs it to read the rest of the interface.
Planning information, not legal or engineering advice. Rules differ by place: check codes and permits with your local authority and your licensed trades.