Videos won't play - step though frame by frame

[clearcomms-france]

I am running Premiere Pro v 14.0 on Windows 10.

I recently completed a large video project successfully,  but a few days after I finished all the editing, something weird happened. It may have followed an automatic Windows update.

Any sequence I load from any project - I have tried several - doesn't play properly.  If the cursor is held over the play button (sithout clicking anything), the video steps through frame by frame, but won't actually play. Clicking the play button has no obvious  effect.

But I have now found that if I click the play button while it is stepping forwards (which should stop it playing), then move the cursor down so the stepping stops, I can now start and stop the video playing normally with the space bar, and only with the space bar!

I have tried uninstalling and reinstalling, to no effect.  I have tried importing working mp4's - same problem when dropped into a sequence.

Also I can't change the size of the windows when a project is loaded, though I can do so when the files are loading.

I've been using various versions of Premiere Pro since the 1990's, and I have never seen anything like this.

I should add that I use Kaspersky Total Security, which has found no viruses.  I have run two further virus checks Using Malwarebytes Pro and MSERT, but they have also found nothing.

I am assuming that either there is a problem with Windows, or I have a conflict somewhere, but have no idea where to look!

Is there a clue in further weirdness? I can play mp4's in Windows Media Player and the Windows Films & TV app, but VLC shows a variant of the "stepping through" behaviour, and looks like it is playing every 25th frame at short intervals!  From the start it won't even do that, but just cycles through the first 3 or 4 frames so moving objects just jerk back and forth.

If anyone can suggest possible remedies I will be very grateful.

Fortunately I have no video projects in the immediate future, and my computer is to be rebuilt and upgraded to Windows 11 in the next few weeks, which hopefully will fix things! But I would like both to understand the cause of the problem, and ideally fix it now!

QAny suggestions will be acknowledged and appreciated.

[Peru Bob]

Delete the Media Cache and Media Cache files:
https://community.adobe.com/t5/premiere-pro/faq-how-to-clear-your-media-cache-in-30-seconds-in-premi...

If that doesn't work, try resetting the preferences:
https://community.adobe.com/t5/premiere-pro/faq-how-to-reset-trash-preferences-in-premiere-pro/td-p/...

If that doesn't work, try resetting the Workspaces:
Reset a workspace
Reset the current workspace to return to its original, saved layout of panels.
1. Do one of the following:
• Click the Workspace menu icon and select Reset to Saved Layout.
• Choose Window > Workspace > Reset to Saved Layout.
from here:
https://helpx.adobe.com/premiere-pro/using/workspaces.html

If that doesn't work, try Preferences > Audio Hardware and set Input to None.

If that doesn’t work, try updating or rolling back your graphics driver directly from the video card manufacturer’s site. If NVIDIA, do a clean installation of the latest Studio Driver (NOT the Game Driver)

If that doesn't work, try creating a new project and import the old one into it.

[Harold Silva]

Hola lamento oir del error; me paso algunas veces y lo solcuione restaurando las preferencias del programa:
CTRL ALT SHIFT e iniciar el programa. Aunque parezca simple soluciona muchos errores.
Espero sea de ayuda.
Otraopcion seria reinstalar el software

Salu2

[Ann Bens · Accepted solution]

@Harold Silva 

Peru Bob already mentioned Trashing Preferences: and btw its Alt+Shift.

Alt resets the preferences and Shift resets the plug-in cache.

[clearcomms-france]

Many thanks for all three replies. I went through Peru Bob's suggestions (I had already cleared the cache) without success.  Then, seeing Ann Bens say I should go the "Alt-Shift" route, I did. Taa-raah!!  It did clear out the old files, and when I opened a project that had previously failed to work, everything was back to normal.

And even VLC Media Player was playing video properly, which to me is VERY odd.

Thank you everyone - problem solved.