@Solla-topee I have this problem too although I cannot format the sd cards. I bought three Kingston canvas 64 gb from Amazon and put in three new kc115's. They worked until they were full and then I got other errors or tome parameter not valid. All three no longer record or playback although I can sometimes see thumbnails. Tried reformatting in camera via app but all failed. Tried formatting on win 10 pc but said corrupted and needed formatting. Did that but camera not recognising and unable to formatt. All three cameras not recording anything. 

Solla-topee wrote

Hello @JessieY 

Kasa Camera with SD card feature will overwrite from the oldest recording automatically after enabled 24/7 recording.   Please check out QA here: 

Q6.9: If the Micro SD card is full of recordings, will the newly recorded videos automatically overwrite the old ones?

• Please ensure kasa camera and Kasa app are updated the latest version.

 

For' all I could see is the thumbnail' may I know what happened when you tap the thumbnail to access video clips? Please share photo of it when if this happen again, thank you.

Some SD card issue are caused by fake SD card, you may also test SD card with H2testw mentioned in the guide here and share a photo.  

What should I do if the SD card doesn’t work properly on my camera?