You can probably fix it by stopping openHAB and removing it from:
/var/lib/openhab2/config/org/openhab/addons.config
The error message was added in 2.5.0-SNAPSHOT because the continuous feature installation causes a lot of load causing all sorts of issues. See also [SOLVED] After upgrade to 2.4 stable I'm flooded with java.lang.IllegalStateException - #12 by wborn.