Blank Time lines

I don't even know to to describe this properly, but here goes.

When i edit, i make a new time line after a major edit. (have done for years)

I do this by copying the time line and then renaming it. (so all the files and time line are the same specs)

Since 17.1 ive randomly found "some time lines" (seems to be the ones created on 17.1) Randomly display black (as in no picture), all the thumb nails and cuts remain visible.

After this happens, it seems to effect all of DaVinci including all the other timelines in the same project that were all playing fine before i went to the random timeline that didn't play.

I have reinstalled Davinci 17.1 with no change.

This is not a corrupt timeline as it happen across different projects and drives.

I really need to find a solution if anyone has has a similar problem

Thank you


Also it will hang Davinci and crash

Date/Time: 2021-03-28 21:13:40 +1000
End time: 2021-03-28 21:14:25 +1000
OS Version: Mac OS X 10.15.7 (Build 19H2)
Architecture: x86_64h
Report Version: 29

Data Source: Stackshots
Shared Cache: 0xb543000 3DDDEC64-FB41-3675-B9E3-CF815ECDC8D6

Command: Resolve
Path: /Applications/DaVinci Resolve/DaVinci Resolve.app/Contents/MacOS/Resolve
Identifier: com.blackmagic-design.DaVinciResolve
Version: 17.1.0 (17.1.00024)
Parent: launchd [1]
PID: 434

Event: hang
Duration: 45.30s
Duration Sampled: 4.40s (process was unresponsive for 41 seconds before sampling)
Steps: 44 (100ms sampling interval)

Hardware model: Macmini8,1
Active cpus: 12

Time Awake Since Boot: 790s