Recently Used Apps crashing in portrait mode
To check logs there are a few options, for instance:


Given that you have a Samsung, try opening SysDump by going to Phone dialer -> *#9900# (no need to press Dial).
To get the logs, you might need to root your phone. This shows methods for accessing files in data/data without rooting, and it may apply to data/log as well.
Use the adb to check the output of dmesg.
Use aLogcat.
Details for checking an app adapted from here, it may require some tweaking for Recently Used Apps, if useful at all:


Start your target app (e.g., "Myapp") on the device. If it crashes, repeat this step 2-3 times.
Next start "aLogCat app" and wait for approximately ~1 minute.
Press the "Menu" button and select "Filter".
Type "Myapp" in the text field and press "OK" button.
Wait for approximately ~1 minute.
Press "Menu" button and select "Share".
Collect the log via any sharing option you have access (e.g., email, Bluetooth).

Use CatLog - Logcat Reader!. You might need root Access.


For completeness, I leave here a few related posts

Android device crash logs?

How can I view and examine the Android log?

https://stackoverflow.com/questions/24407984/how-to-locate-app-crash-logs-in-android-phone

https://stackoverflow.com/questions/24305180/error-erasing-old-data-from-logcat