Due to a problem in the Intel® Quartus® Prime Pro software version 19.1, you may see this error in terminal when you run Design Space Explorer.
quartus_dsew: /build/swbuild/SJ/nightly/19.1/240/l64/acds/quartus/h/nlohmann/nlohmann/json.hpp:15590: const value_type& nlohmann::basic_json::operator[](T*) const [with T = const char; ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long int; NumberUnsignedType = long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; JSONSerializer = nlohmann::adl_serializer; nlohmann::basic_json::const_reference = const nlohmann::basic_json<>&; nlohmann::basic_json::value_type = nlohmann::basic_json<>]: Assertion `m_value.object->find(key) != m_value.object->end()' failed.
To work around this problem, remove this file:
~/.altera.quartus2/notifications.conf
This problem is fixed starting with the Intel Quartus Prime Pro Edition software version 20.1.