CMK Updater error after update 2.0.0p26

CMK version: 2.0.0p26
OS version: Windows Server 2019

Error message:

C:\Program Files (x86)\checkmk\service>check_mk_agent.exe updater
unacceptable character #x0000: special characters are not allowed
  in "<unicode string>", position 0

C:\Program Files (x86)\checkmk\service>check_mk_agent.exe version
Check_MK Agent version 2.0.0p26
C:\Program Files (x86)\checkmk\service>

funny thing is that a register is working, but updater is not able to run. any ideas for that or a reinstall is needed?

repair installation did the trick. but i guess there must be some issue in the upgrade mechanism or no hash validation or so.