Can you provide a screenshot?

Sorry for the delay.

Here's a screenshot of the viewport under the solid display

Here's a screen shot of the viewport under the rendered display

Here's a eevee rendered image from the file above

Here's a eevee rendered image from another file (The body, hair, and barrettes all have one material each, but the eyes have two and this is the result when rendered in eevee. The eyes also appear transparent in the solid display as shown below)

Below are all images rendered on the same settings in Cycles (the images still appear with it's transparent counterparts in the viewport but render okay)

I opened the .blend file on 2.81a, I got no problems like transparency, may be you can try restoring blender setting to defaults and see whether the result changes.

I just tried it and it's no good. Is it possible that the file got damaged while being downloaded and installed? The last version of blender I used, I downloaded the zip and installed it on my computer. This time I used to the installer. Is there too much difference in how Blender functions based on how it's installed?

No, both portable and installation version should work same.

I tried Blender's debugger, something that's standing out to me is the 'GL API other: Texture state usage warning: Waste of Memory: Texture 0 has mismaps, while it's min filter is inconsistent with mipmaps' It shows up a lot, but I don't know what that means.

Here is the file below if it helps

Please upload the blender_system_info.txt file.

Also, try using the latest daily build from

https://builder.blender.org/download/