You need to re-flash the TWRP file via fastboot.

Go to this thread: https://forum.xda-developers.com/htc-10/how-to/2016-05-27-fastboot-flashing-firmware-t3387520

Read the instructions before flashing anything. Make sure you choose the right file. Refer to this post: https://forum.xda-developers.com/showpost.php?p=72875043&postcount=2059

If you’re encrypted, you need to format (different than wipe. You have to type “yes” in TWRP) your internal storage. This will wipe everything from your internal storage including TWRP folder with backups, titanium backup, etc. If you have anything you want to keep, move it to external storage or back it up to the computer before proceeding. If you’re not encrypted, just do a normal wipe (system, cache, dalvik, data) and flash the ROM, gapps, and either SuperSU or Magisk for root.

So you want to enter the competitive world of professional ROM flashing? If so, you need to take your phone flashing to a new level. How can you position yourself and your expertise so you are the dev's obvious choice? Be honest. Do you enjoy troubleshooting? Do you have a problem with things going wrong? If so, then you might be better off staying on your current OS.If you are still reading this and are sitting in your chair thinking: “I could do that, if I tried”, then maybe you have a chance.If you can't read, watch this video: https://youtu.be/JmvCpR45LKAQ: I flashed an update and lost TWRPA: If you have access to a computer, go to 1. No computer and s-off go to 2. No computer and s-on go to 3.Q: How can I prevent the loss of TWRP when updating?A: You need to flash root to prevent TWRP from being overwritten.Note that this is only true for older builds as of July 2017. The problem with TWRP has been resolved as of the first official release of July 2017.Q: I’m coming from Viper or some other stock-based ROM. What do I need to do?A:Q: I want to use this ROM, but I don’t want root. Is that possible?A: You’re in luck. This ROM does not come pre-rooted. So you can use this with no root if you desire. Although, I’m not sure why you would want to do that, but you can.Q: My phone reboots randomlyA: Use adb or any other file explorer tool to pull a copy of /sys/fs/pstore/console-ramoops (command: adb pull /sys/fs/pstore/console-ramoops) after the reboot and post that. Try to include what you were doing when experiencing the reboot. Also refer to the next question before filing any reports.Q: I’m having weird crashes/rebootsA: Do you have other third party software installed such as a different kernel, Magisk, sound mods, etc.? Remove all of these before submitting a bug report. Reports made with unsupported software like what is listed above will not be addressed.Q: Will this ROM receive frequent Security Updates?A: YesQ: Does this ROM pass SafetyNet?A: It should if you don’t flash root when installing the ROM, since it doesn’t come loaded with root out of the box. If you want root, Magisk will allow you to pass SafetyNet.Q: Does OTA work?A: YesQ: Do I need to do a clean install?A: If you’re coming from another ROM, yes. If you’re already running ours, a dirty flash should be fine unless otherwise specified. If you have problems, try a clean flash before reporting issues. Refer to an above question if you are coming from a stock-based ROM or are possibly encrypted.Q: Will you add stuff to the ROM?A: *insert perhaps cow meme here*Q: Is this a Sense based ROM?A: NoQ: Does the camera work?A: See the OP for current stuff not workingQ: Will Stock camera work on this ROM?A: No