Premiere Elements 13 on Windows 8.1 64 bit.
Have you updated 13 to 13.1 yet using an opened project's Help Menu/Updates? And, if you have, did the present problem exist before and after the update from 13 to 13.1? And, if you have not, please update 13 to 13.1.
What are the properties of your source video and what have you (manually) or the project (automatically) set as the project preset to match the properties of the source video? See Edit Menu/Project Settings/General. Giving the brand/model/settings of the camera that recorded the video may give us the properties information that we need for troubleshooting.
Is there an orange line over the Timeline content when you attempt the play in the Edit area monitor? If so, Timeline render the content by pressing the Render button above the Timeline. The orange line will turn green when the Timeline rendering is complete. Timeline rendering is a preview feature. This question/answer may trace back to your project settings.
Is your video card/graphics card up to date according to the web site of the manufacturer of the card or the manufacturer of the computer?
Does the problem exist with or without the antivirus and firewalls disabled.
In Edit Menu/Preferences/General, there is a preference named Use Hardware Acceleration (works on Intel HD Graphics 2000 and higher). Please look at your issue with and without this preference disabled.
Let us start here and then decide what next based on the details and results in your reply.
First, thanks for your detailed answer.
Sorry even though I'm a long time digital Audio user, I'm a newbie with video, so perhaps my terms will be sometimes inappropriate.
I'll try to answer to each point but I'm not on the computer that I use for video things.
I had the problem withPE 13 and I updated to 13.1. Problem remained the same.
Properties of my projects match the properties of video sources.
They are AVCHD 1920*1080 50p coming mostly from Panasonic HC-X920 and sometimes from Gopro Hero4 Silver.
I usually make a render each time I can see orange line on my timeline.
My video card is up to date (last auto update is from 29th of july).
I'll have to check when I'll be back on the video PC with or without antivirus and firewall, same thing for the Use hardware acceleration option.
I'll let you know quickly.
Thanks again for your help.