A client sent an image to me from her Silhouette/Cameo software (.studio file type, or something).  I converted it to SVG in my Cameo software, and then opened it in Inkscape 1.1 (which I only installed a couple days ago).

I ungrouped everything & unioned it all together, then changed the color fill to white.  I then exported it as an PNG.  I believe this was my first PNG export using a file CREATED in 1.1.  This is where it gets hairy.  It would not export with a transparent background, no matter what I did.  I thought maybe the 1.1 version had a different background opacity, so I started searching for "how to make the background transparent".  I found a YouTube video that demonstrated how to turn the white background to the checkerboard... and then he turned the Alpha channel down from 100 to 0.  Admittedly, I'm not sure I understand what that does, but I did it.  Didn't help with my PNG export, though.  It still exports as a solid white rectangle, the full size of the page size for that image (8" x 13.75").  I tried creating new font... colored it white... exported it, still a solid rectangle.  Tried using color... solid rectangle.  I saved the file & tried opening it on my previous laptop, which is running 0.92.5... but it still exports as a solid rectangle.  

Fast forward to today... In 1.1, I opened a file originally created in 0.92.5.  Created & edited what I needed, exported it as PNG, and it exported perfectly with transparent background.  I then got the idea to try the troublesome file from the day before.  Opened the previous file, that was created in 1.1, copied the image & pasted it into the file originally created in 0.92.5 (but opened in 1.1).  Tried exporting it as PNG, and it exported perfectly with transparent background.  

SOOOOO... all that to say... what the heck have I done to the 1.1 version to make new 1.1 files not export transparent??   I honestly don't believe I've changed anything other than the checkerboard background checkbox, and the Alpha Channel slider - though, I tried "undoing" those things, and the export still didn't work.  

Hopefully what I've described makes sense.  I feel like it follows exactly the actions I've taken & it "makes sense" to me, but I have the unfair advantage of having done it... so, if it all sounds like cluttered gibberish, let me know & I'll try to unpack it from my A.D.D. brain & make some sense of it.  LOL.  I'll be working on my PC most of the day in case anyone has suggestions to try or needs further info/screenshots.  I'm really hoping this isn't a "downgrade to 0.92" fix... I (mostly) love the new 1.1 version. 

Thank you for your time & insight!!
Cathy

Again? Isn´t this the same issue you opened here already? https://inkscape.org/forums/questions/white-object-is-transparent/

No...  O_o   That's an issue with an object that is SUPPOSED to be white, but is showing transparent, or partially transparent (never did figure that one out though.  I just gave up & "redneck rigged" it by removing the inside stroke path line.  Not a solution, but it fixed that particular issue so I could get the print done).   This is a file (that just happens to also be white, but I could change it to any color if that would help distinguish between the two issues) that I'm trying to export as a transparent background PNG, but instead exports as a solid rectangle.  While they both deal with a white image component and transparency, I assure you, they're totally separate.  I simply gave the steps to the only settings changes I've made within the software since I installed it, in case that relates to the issue. 

Tyler advised you to reset Preferences which you refused to and I guess you didn´t try my file from the other thread. Not sure how to help any further.

I don't understand your sarcasm & rudeness.  I didn't "refuse" to do anything... I'd sure appreciate you pointing out where I refused to try his suggestion.  And if you're referring to where I commented that it's a new install, I'm not sure what part of the country you're from, but where I am, that's not a refusal.  It's simply a statement of fact that I believe to be true.  I have never experienced software settings saving from an older version to a new version, especially when the new version install is an initial install on a new PC, not an upgrade.  For what its worth, resetting the preferences did not correct the issue.  And just to be thorough, I also tried the steps Marco suggested.  Again, with no success to fixing my issue.  As mentioned in my previous comment, I gave up on that problem, which is why I did not keep commenting on that thread.  I didn't want to waste anyone else's time since I had found a workaround.  I'll happily link the SVG file for you so you can see what it's doing.  Maybe you can point out all the things I've done wrong with it so I can correct them for future images. 

And no, I didn't "try your file" from the other thread.  What in the world was I supposed to be trying with it?  Did you want me to download it & try opening it to see if it opens the way you think it should?  Actually saying that would have been a good idea.  My apologies for being already extremely frustrated with my file & not being able to read your implied suggestions.  

If you could drop the attitude, tha'd be great.  If not, that's cool too... I also think the conversation would be a lot less irritating to you if you'd actually read my comments & not just assume.  Don't assume a statement I make is a "refusal" to a suggestion... don't assume I know what you're wanting me to do when you upload a file... and don't assume the two threads I've posted are redundant simply because the words "white" and "transparent" are in both topics.   I feel like I've explained it all pretty well.  Not sure how to help explain it any further. 

Please share the svg files that will not export with transparency... two if you can: the svg direct from Cameo, and the Inkscape file after union and white fill.

Additionally, just to be sure, please take a screenshot of the PNG export dialog settings when you export. Anything specific selected in the Advanced section?

Here are both SVG files, as well as the exported PNG.  I'll get a screenshot of the PNG export details... 

Here's the SVG file that I actually got to export the PNG correctly.  This is the one that was originally created in version 0.92.5... 

Select a transparent canvas background in the Quick Setup tab on your Welcome screen, click the save button (the Inkscape specific code is saved to preferences.xml). 

All new or opened documents based on a SVG file (or template) without this Inkscape specific code will inherit this settings from preferences.xml. Inkscape specific code is saved to Inkscape SVG, not to Plain SVG.

Aero

Select a transparent canvas background in the Quick Setup tab on your Welcome screen, click the save button (the Inkscape specific code is saved to preferences.xml). 

Thank you for your response!  I did as you suggested and chose a Dark background from the welcome screen.  I clicked Save... then the Thanks button... and then New Document.. but still, a light checkerboard background came up.  I tried resetting the System Preferences (again) just in case I arbitrarily boogered something up since the last time I clicked reset, but it did not do anything differently.  I have closed & restarted Inkscape 3 or 4 times, and selected one of the Dark backgrounds each time.  I genuinely don't know what I'm doing wrong here... and I'm certainly no rookie.  Clearly I'm no expert either, but I feel like there's something I'm missing.  Probably something extremely obvious that's staring me in the face, and I'm just not seeing it.  **facepalm**  Is it possible a default template could be overriding the welcome screen preferences?  It appears I saved a new default template after following the YouTube steps for setting a transparent background.  I assume this is why the document properties still show the transparent/white checkerboard selection......... and I may have just found the 'obvious' staring at me.  When I hover over the "background color" in the document properties, it says "Note: opacity is ignored except when exporting to bitmap".  Does that mean it's ignoring the fact that I want a transparent background, and is making my PNG export background opaque white?  Even with the alpha channel at 0?

Attached - the welcome screen, showing which background I selected.. and then also the New Document that resulted from it.  

Aero, 

I believe, because of your suggested background setting changes, I have managed to answer my own question... I just opened the SVG file that I saved after resetting the preferences, unchecked the checkerboard background box in the document properties, and then exported the PNG....  it exported with a transparent background!!  HALLELUJAH!!  THANK YOU!!!!

Now... how do I undo this awful default template I've managed to save??  I like the dark checkerboard from the welcome screen drop down, but I'm not sure how to get that to come up so I can re-save a new default template since the current default template has this screwy alpha channel background.

The DEFAULT.svg shown in your picture is called a user template. Just delete it.

Inkscape do have another default.svg in it's install folder that will be used instead as soon as you delete yours.

SWEET MARY!!!  Dare I say, I think it's fixed???  So far, it seems to be working correctly now... THANK YOU SO MUCH for your help & guidance!!  It's much appreciated!! 

You're welcome.😊