Sony recently pulled their latest firmware 4.0 and 2.0 for their PXW-FS5 and Z150 respectively, due to some issues with shooting HLG in camera. The good news, is that just earlier today, Sony released a fixed version of the firmware – now called firmware version 4.02 and v2.02 for the two cameras in question.
   

As a reminder, apart from adding in-camera Hybrid Log Gamma profiles for HDR delivery, Firmware version 4.0 (and new fixed v4.02) adds a new 120fps continuous slow-motion option in 1080p to the Sony FS5. This is certainly a huge addition to the already very capable 4K camcorder, unfortunately it will require a separate paid license (CBKZ-FS5HFR, which is priced at $499 in the US) in order for the new slow motion frame rate to be selectable in your camera’s menu.

At the moment, prior to Firmware 4.0, the Sony FS5 was limited to 1080/50/60 continuous slow-mo in camera.

PXW-FS5 Firmware V4.02 Details:

Issues Fixed:

• Video image may be recorded with short delay of 2 or 3 frames of audio in other recording modes than AVCHD.
• When choosing [HLG1],[HLG2] or [HLG3] in the PictureProfile and CENTER SCAN in the CAMERA/PAINT menu, rebooting the camera may cause brightness and colour shift.

Download Firmware v4.02 for Sony FS5 from this link here.