Cnt flash any RUU

Hey Guys,

No matter what RUU i flash, I always want to get the error code 155.
But i Relock my Bootloader with htc_fastboot oem lock and the Bootloader say's relocked.

what can do?
my phone is an German O2
cidnum: HTC__102


Please excuse my bad language.

Greetz from Germany.

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