Most people are averse to change at some level, and a certain amount of unease when it comes to change is normal. It only becomes a problem when a person is so determined to keeping things the same—possibly because they don't want to give up control or are afraid of the unknown—that their quality of life is impacted, relationships are damaged, and they're unable to grow and evolve in a healthy manner.

Dismissing new ideas without considering them
Humoring people; giving the appearance of considering something new but always rejecting the opportunity
Avoiding making decisions that require change (so the status quo can be protected)
Reacting emotionally rather than logically
Using outdated sources or ineffective arguments to make a point
Becoming emotionally activated when new ideas are being considered
Clinging tightly to "old school" methods: resisting technology, ignoring scientific advances, rejecting tools that deviate from what they're used to, etc.
Sentimentality
Loyalty (to people, a job, a community, etc.)
Inflexibility
Repairing and fixing material objects rather than replacing them
Living in the same house even when it's falling apart or the property value has skyrocketed
Sticking close to home; not traveling far or taking long trips
Frequent strife with family members who want to make changes the character is resistant to
Resenting others for moving on and leaving the character behind
Going to extremes to avoid change (manipulating others, lying, being mean or lashing out at someone who is suggesting a change, etc.)
Being more interested in the past than the future

Disliking being left alone/behind but being unable to embrace the changes required to keep up with others
Feeling obsolete
Feeling selfish for being so unbending but not knowing how to be more flexible
Wanting to go back in time to when things were happier or simpler
Struggling with anxiety or depression
Feeling stuck in a situation but being unwilling to make changes

CONFRONTATIONAL, CONTROLLING, CYNICAL, DEFENSIVE, EVASIVE, HOSTILE, IGNORANT, INFLEXIBLE, IRRATIONAL, JUDGMENTAL, NERVOUS, OBSESSIVE, OVERSENSITIVE, PARANOID, POSSESSIVE, RESENTFUL, STUBBORN, UNCOOPERATIVE

Staying in a situation that makes the character unhappy or is unhealthy because it's preferable to facing the unknown
Difficulty making even small changes to a daily routine
Missing out on meaningful activities with others (a trip with friends, a family reunion, dinner at a friend's house, etc.)
Becoming isolated from others
Difficulty utilizing modern advances that most people enjoy because the learning curve is too great
Always having to make excuses for turning down an opportunity
Avoiding people who are likely to suggest activities or changes that threaten the character
Always needing to do things their own way; resisting new methods or ideas that would make their life easier

A NATURAL OR MAN-MADE DISASTER, A NOMADIC CHILDHOOD, A PARENT'S DIVORCE, BATTLING A MENTAL CONDITION, BEING FORCED TO LEAVE ONE'S HOMELAND, DISCOVERING A PARTNER'S SEXUAL ORIENTATION SECRET, DIVORCING ONE'S SPOUSE, EXPERIENCING THE DEATH OF A PARENT AS A CHILD OR YOUTH, LIVING WITH A CRITICAL MEDICAL DIAGNOSIS, LOSING A LIMB, LOSING A LOVED ONE TO A RANDOM ACT OF VIOLENCE, LOSING ONE OF THE FIVE SENSES

New technology or processes at work that must be learned and used
A scenario requiring the character to move (the house being condemned, no longer being able to pay rent, etc.)
A spouse having to move into a retirement home, leaving the character on their own
Grown children moving across the country and asking the character to come with them
The culture shifting to embrace ideas the character disagrees with
Being given a new phone, a computer, or some other tool the character isn't comfortable with but must learn to integrate into their life
The character's children wanting to deviate from a long-held tradition

Self-Actualization: A fear of change usually leads to stagnation, with the character not embracing ideas and practices that would improve their life and provide better opportunities.
Love and Belonging: The character's important relationships can become strained if those people are limited by the character's change-averse choices.
Safety and Security: A character who fears change may stay in an unhealthy relationship or unsafe living environment because they prefer the devil they know to the devil they don't.

ACHIEVING SPIRITUAL ENLIGHTENMENT, BEATING A DIAGNOSIS OR CONDITION, COMING TO GRIPS WITH A MENTAL CONDITION, COPING WITH A LEARNING DISABILITY OR ILLNESS (KIDLIT), ESCAPING HOMELESSNESS, ESCAPING WIDESPREAD DISASTER, FINDING ONE'S PURPOSE, HAVING A CHILD, NAVIGATING A CHANGING FAMILY SITUATION (KIDLIT), OVERCOMING A DEBILITATING FEAR, OVERCOMING A FEAR (KIDLIT), OVERCOMING ADDICTION, RECONCILING WITH AN ESTRANGED FAMILY MEMBER, TRYING SOMETHING NEW (KIDLIT)

A CHILD WANTING TO LIVE WITH ONE'S EX, A COMPETITOR SHOWING UP, A DIVORCE OR BREAKUP, A FAMILY MEMBER DYING, A LOVE INTEREST TAKING UP WITH SOMEONE ELSE, A NATURAL DISASTER, A PARTNER LOSING THEIR JOB, A PLACE OF SAFETY BEING COMPROMISED, A RECESSION OR ECONOMY CRASH, AN ANTICIPATED EVENT BEING CANCELED, AN ELDERLY PARENT REQUIRING CARE, AN UNEXPECTED CHANGE OF PLANS, AN UNEXPECTED LOSS OF PRESTIGE OR WEALTH, AN UNEXPECTED PREGNANCY, BEING ASSIGNED AN UNDESIRABLE PARTNER, BEING CAST OUT OF A GROUP, BEING CUT FROM A TEAM, BEING EVICTED, BEING FORCED TO MARRY, BEING INJURED, BEING SADDLED WITH UNEXPECTED RESPONSIBILITY, BEING THRUST INTO THE SPOTLIGHT, CHILDCARE FALLING THROUGH, DISCOVERING A SPOUSE'S SECRET, DISCOVERING ONE HAS A CHILD, HAVING TO LEAVE ONE'S HOME OR HOMELAND, HAVING TO MOVE, LOSING A JOB, LOSING A SOURCE OF TRANSPORTATION, WAR BREAKING OUT, WORK-LIFE BALANCE BEING THREATENED