Unable to change any data for single record in table. I keep getting a write conflict message. All other data in table can be changed - ms-access

Question

As stated above, I am unable to change any data in a single record of a table. No other users are in the table or database. I do not have other copies of the database open. I keep getting a write conflict error, with only the "copy to clipboard" and "drop changes" options available to select. Is there any other explanation for why I'd be getting a write conflict error for one record in this table? Could there be something in the VBA that is locking this record? I am able to edit other records in the table, but this single record seems to be locked.
EDIT: as requested by #Andre, here is the full CREATE TABLE statement
CREATE TABLE [dbo].[2450Other_t1](
[ID] [int] NOT NULL,
[UPN] [int] NULL,
[CRID] [int] NULL,
[bmt_date] [datetime] NULL,
[Visit] [nvarchar](5) NULL,
[ContributingCOD] [nvarchar](40) NULL,
[NewMalignancyEBV] [nvarchar](5) NULL,
[DiseaseStatusNorCR] [nvarchar](25) NULL,
[SUBSEQ_T] [nvarchar](5) NULL,
[Ind_Subseq] [nvarchar](25) NULL,
[Source_Subseq] [nvarchar](255) NULL,
[CellTherapy] [nvarchar](25) NULL,
[Date_CT] [datetime] NULL,
[GraftFail] [nvarchar](5) NULL,
[AGVHDDevelop] [nvarchar](5) NULL,
[date agvhd] [datetime] NULL,
[date agvhd prior] [nvarchar](5) NULL,
[grade at diag] [nvarchar](10) NULL,
[skin] [int] NULL,
[gut] [int] NULL,
[ugi] [int] NULL,
[liver] [int] NULL,
[other_sites] [nvarchar](25) NULL,
[date max agvhd] [datetime] NULL,
[cghvd develop] [nvarchar](5) NULL,
[cgvhd persist] [nvarchar](5) NULL,
[max cgvhd] [nvarchar](10) NULL,
[date max cgvhd] [datetime] NULL,
[on steroids] [nvarchar](5) NULL,
[other ist] [nvarchar](5) NULL,
[Liver Therapy] [nvarchar](5) NULL,
[liver agents] [nvarchar](25) NULL,
[VodDevelop] [nvarchar](5) NULL,
[vod date] [datetime] NULL,
[chimerism] [nvarchar](5) NULL,
[best-no cr] [nvarchar](255) NULL,
[best pcr] [nvarchar](5) NULL,
[best pcr detect] [nvarchar](5) NULL,
[best pcr date] [datetime] NULL,
[best flow] [nvarchar](5) NULL,
[best flow detect] [nvarchar](5) NULL,
[best flow date] [datetime] NULL,
[best cyto] [nvarchar](5) NULL,
[best fish] [nvarchar](5) NULL,
[best fish detect] [nvarchar](5) NULL,
[best fish date] [datetime] NULL,
[best karyo] [nvarchar](5) NULL,
[best karyo detect] [nvarchar](5) NULL,
[best karyo date] [datetime] NULL,
[best rad] [nvarchar](5) NULL,
[best rad detect] [nvarchar](5) NULL,
[best rad date] [datetime] NULL,
[best clin] [nvarchar](5) NULL,
[best clin detect] [nvarchar](5) NULL,
[best clin date] [datetime] NULL,
[post-syst] [nvarchar](5) NULL,
[post drug1] [nvarchar](50) NULL,
[post drug2] [nvarchar](50) NULL,
[post drug3] [nvarchar](50) NULL,
[post drug4] [nvarchar](50) NULL,
[rlp prior] [nvarchar](5) NULL,
[rlp intv] [nvarchar](5) NULL,
[rlp reason intv] [nvarchar](50) NULL,
[rlp clin] [nvarchar](5) NULL,
[rlp rad] [nvarchar](5) NULL,
[rlp cyto] [nvarchar](5) NULL,
[rlp flow] [nvarchar](5) NULL,
[rlp pcr] [nvarchar](5) NULL,
[rlp chim] [nvarchar](5) NULL,
[rlp date intervent] [datetime] NULL,
[rlp drug1] [nvarchar](50) NULL,
[rlp drug2] [nvarchar](50) NULL,
[rlp drug3] [nvarchar](50) NULL,
[rlp drug4] [nvarchar](50) NULL,
[current not cr] [nvarchar](20) NULL,
[rlp drug5] [nvarchar](50) NULL,
[rlp drug6] [nvarchar](50) NULL,
[rlp drug7] [nvarchar](50) NULL,
[rlp drug8] [nvarchar](50) NULL,
[MaxSkin] [int] NULL,
[MaxGut] [int] NULL,
[MaxUgi] [int] NULL,
[MaxLiver] [int] NULL,
[MaxOther] [nvarchar](25) NULL,
[ScndMalig] [nvarchar](3) NULL,
[scndMaligDate] [datetime] NULL,
[2cndDoc] [nvarchar](3) NULL,
[2NDMALIGDONOR] [nvarchar](7) NULL,
CONSTRAINT [2450Other_t1$PrimaryKey] PRIMARY KEY CLUSTERED
(
[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]