PRE 2018 - Playback blank, also render fails, export is blank

I'd start by installing Quicktime, as we recommended above, and seeing if that makes a difference.

Adobe is trying to divest its products from dependence on Quicktime -- but some video formats still require it if you're planning to edit it in Premiere elements.

Here is the info you all asked about plus some more backstory to help.

I have a new Dell PC using Win 10 Pro so I have not installed QuickTime. I did have QuickTime on my Win 8.1 PC running PrE 12 and it worked perfectly on that old PC setup.

PrE 2018 states, at least what I thought is, native QuickTime support. Also I opened it in normal Premiere and I am pretty sure it worked perfectly (I downloaded the trial version). For what I do PrE/PSE is what I want because the pro versions are overkill and have steep learning curves for me.

These are family 8mm movies from the 50's & 60's I had converted by a respected firm in NY. So they gave me the files in this format. I am working with the original files the company converted for us.

MediaInfo:

General

Format                                   : MPEG-4
Format profile                           : QuickTime
Codec ID                                 : qt   2005.03 (qt  )
Overall bit rate mode                    : Variable
Overall bit rate                         : 132 Mb/s
©TIM                                     : 01;44;06;11
©TSC                                     : 30000
©TSZ                                     : 1001

Video
ID                                       : 1
Format                                   : ProRes
Format version                           : Version 0
Format profile                           : 422
Codec ID                                 : apcn
Duration                                 : 22 min 10 s
Bit rate mode                            : Variable
Bit rate                                 : 132 Mb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 29.970 (30000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:2
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 2.120
Stream size                              : 20.4 GiB (100%)
Writing library                          : Apple
Language                                 : English
Encoded date                             : UTC 2016-04-29 20:55:45
Tagged date                              : UTC 2016-04-29 20:55:45
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709
Menus                                    : 3

Other
ID                                       : 2
Type                                     : Time code
Format                                   : QuickTime TC
Duration                                 : 22 min 10 s
Time code of first frame                 : 01:44:06;11
Time code, striped                       : Yes
Language                                 : English
Encoded date                             : UTC 2016-04-29 20:55:45
Tagged date                              : UTC 2016-04-29 20:55:45

Menu
ID                                       : 3
Codec ID                                 : text
Duration                                 : 22 min 10 s
Title                                    : Chapter Track
Language                                 : English
Encoded date                             : UTC 2016-04-29 20:55:45
Tagged date                              : UTC 2016-04-29 20:55:45
Menu For                                 : 1
01:44:06.340                             : 24

Quicktime installed?

I'm not sure what you meant by "and opened them in PRE 2018".  Are you using PrE 2018 to open a project you started in PrE 12?  Or are you adding the original, unedited clips through the Add Media procedure?

There was another topic yesterday where someone was having trouble with prores files.  That itself may be an issue.