As a workaround, after tapping the Edit button, you can drag one finger over the checkmark circles on the left of each file. Don't lift your finger but swipe right down to the end of the list over the toolbar and it will automatically scroll down and select all files. 

It should be fixed in Textastic 9.2.

Thank you, I could reproduce the problem. It will be fixed in the next update.

I'm glad to hear that it works now. 

I'm aware of a crash when you have a beta version of iOS 13.4 installed. Installing the release version fixes the problem.

Which iPadOS version is installed?

Hello,

can you please tell me any details?

What did you do before the crash happened? On which device model is this? Do you have any custom syntax definitions or themes installed?

You can try to go to the Settings app -> Textastic and check "Reset Recent Files" and then try to start the app. This will clear the list of recent files and prevent the restoration of opened files.

I'd also try a reboot of the device if this doesn't help.

Thanks for the video. Can you please send me the text file so I can try to reproduce the bug?

Textastic does support SFTP remote connections. See https://www.textasticapp.com/v9/manual/remote_servers/sftp_ftps_ftp.html