nnot consist of statements which are essentially mere promises or forecasts of future developments or conditions; and it must be established by clear and convincing evidence. Where the ground of attack is solely and exclusively fraud and no question of mutual mistake is involved, evidence that the physician of the defendant made the positive statement to plaintiff that his injuries were slight and temporary and that he would recover within a short time, or where the claim adjuster of the defendant stated to plaintiff that the physician had made such a statement, is not enough to warrant the setting aside of the release even though plaintiff relied upon it, if its falsity was unknown to the physician making it. It must be shown that the statement was either known to be false by the person making it, or was recklessly made in disregard of its truth with intent to deceive plaintiff, and that plaintiff relied and acted upon it. Chicago, R.I. P. Ry. Co. v. Burke, 73 Okla. 258, 175 P. 547; Midland Valley R. Co. v. Clark, 78 Okla. 121, 189 P. 184; Davis v. Higgins, 95 Okla. 32, 217 P. 193; Chicago, R.I. P. Ry. Co. v. Perkins, 115 Okla. 233, 242 P. 535. The attack on this release which the trial court sustained was that of mutual mistake. It is equally well settled law in Oklahoma that a release may be voided for mutual mistake of a past or present fact, material to the agreement; but it will not be set aside where the mistake is one of prophecy or opinion respecting the probable future developments or permanency of a known injury. When a release is challenged for mutual mistake, evidence clearly and convincingly establishing an innocent misrepresentation by a physician of the defendant in respect to the extent of the injuries sustained by plaintiff or the existing condition of plaintiff, made with intent that it be acted upon, and is relied upon by him, warrants cancellation of the instrument.

In the absence of fraud or mistake, an executed agreement of settlement is as conclusive against a party seeking to avoid it as the final judgment of a court of competent jurisdiction. Midland Valley Rwy. Co. v. Clark, 78 Okla. 121, 189 P. 184 (1920). In this cause there is neither an allegation of fraud or mistake, nor evidence in the record to bring them to the fore as issues.

The court remarked that, "It is the policy of the law to encourage the settlement and compromise of controversies as a discouragement to litigation," and, "A written contract cannot be avoided on slight or frivolous grounds." To the same general effect see Midland Valley R. Co. v. Clark (1920), 78 Okla. 121, 189 P. 184, wherein this court said in part in paragraph one of the Syllabus: "* * * The burden is always upon the assailant of the contract to establish the vice which he alleges induced him, and a bare preponderance of evidence will not sustain the burden.

The question of fraud was not present. While the decision in the Burke Case has not been specifically overruled, the decision in the case of Davis v. Higgins was a direct disapproval of the proposition therein expressed that mutual mistake may amount to constructive fraud in such cases. In Midland Valley Ry. Co. v. Clark, 78 Okla. 121, 189 P. 184, cited by plaintiff, the facts disclosed were wholly dissimilar to the facts in the present case. There the plaintiff was ignorant and unable to read and was constantly pursued by defendant's claim agent.

HARRISON, J. This case is here on a second appeal. It was here before on appeal from a verdict and judgment obtained against plaintiff in error by this defendant in error in the district court of Kay county, December 3, 1917. An opinion was rendered in the former appeal April 20, 1920 (Midland Valley Railroad Co. v. Clark, 78 Okla. 121, 189 P. 184), affirming the judgment of the trial court. Mandate issued from this court to the trial court of Kay county, May 11, 1920, and was spread of record in said court, May 12, 1920.

"No judgment shall be set aside or new trial granted by any appellate court of this state in any case, civil or criminal, on the ground of misdirection of the jury or the improper admission or rejection of evidence or as to error in any matter or pleading or procedure, unless, in the opinion of the court to which the application was made, after an examination of the entire record, it appears that the error complained of has probably resulted in a miscarriage of justice, or constitutes a substantial violation of a constitutional or statutory right." Dunn v. Modern Foundry Mach. Co., 51 Okla. 465, 151 P. 893; Midland Valley R. Co. v. Clark, 78 Okla. 121, 189 P. 184; Brownell v. Morehead, 65 Okla. 219, 165 P. 408. In the last case cited the court uses this language:

" Also, the cases of Morton v. Roberts, 88 Okla. 263, 213 P. 297, Midland Valley R. Co. v. Clark, 78 Okla. 121, 189 P. 184, and many other authorities are cited in support of this rule, which releases the appellee from the effect of the agreement as entered into, and, also, the case of C., R.I. P. Ry. Co. v. Rogers, 60 Okla. 249, 159 P. 1132, is cited as an authority distinguishing between fraud and misrepresentation and mistake of fact, from which we quote the following: "The plaintiff was advised by Mr. Brady, the claim agent, that the physicians of the company had reported the injury as merely a skin wound, and that it was not permanent. He was advised by Dr. Tye and Dr. Border, physicians of the company, that the injury was merely a skin wound, and not permanent. He was advised by Dr. Tye that he would have a good leg and would be able to perform labor to the extent and in the capacity he did prior to the injury. The plaintiff was a mere employe of the company.

"When the instruction of the court has in substance that which is requested in a special instruction, then it is not error for the court to refuse to give the special instruction." In Midland Valley Ry. Co. v. Clark, 78 Okla. 121, 189 P. 184, the rule is stated as follows: "No judgment will be set aside or new trial granted by an appellate court of this state in any case upon the ground of misdirection of the jury unless, in the opinion of the court to which the application is made after an examination of the entire record, it appears that the error complained of has probably resulted in a miscarriage of justice, or constitutes a substantial violation of a constitutional or statutory right."

See Birch v. Keen, 449 P.2d 700 (Okla. 1969) (not an F.E.L.A. case); Midland Valley R.R. v. Clark, 78 Okla. 121, 189 P. 184 (1920) (an F.E.L.A. case long antedating the Dice Decision above). We conclude that the trial judge should not have relied upon the Oklahoma case of Birch v. Keen, supra, in his memorandum decision in reaching his determination that there was no genuine issue of fact.